Log file for your reference:
##[debug]Evaluating condition for step: 'PowerApps Import Solution 1'
##[debug]Evaluating: succeeded()
##[debug]Evaluating succeeded:
##[debug]=> True
##[debug]Result: True
##[section]Starting: PowerApps Import Solution 1
==============================================================================
Task : PowerApps Import Solution
Description : PowerApps Import Solution
Version : 0.1.2
Author : Microsoft
==============================================================================
##[debug]VstsTaskSdk 0.11.0 commit 7ff27a3e0bdd6f7b06690ae5f5b63cb84d0f23f4
##[debug]Entering D:\a\_tasks\PowerAppsImportSolution_9f15c5c5-3882-4d37-af7d-8a42a406002a\0.1.2\ImportSolution.ps1.
##[debug]Loading module from path 'D:\a\_tasks\PowerAppsImportSolution_9f15c5c5-3882-4d37-af7d-8a42a406002a\0.1.2\PowerApps-SharedFunctions.psm1'.
##[debug]Exporting function 'Get-ServiceConnection'.
##[debug]Exporting function 'Get-PSCredentialFromServiceConnection'.
##[debug]Exporting function 'Get-ServicePrincipalInfoFromServiceConnection'.
##[debug]Exporting function 'Get-BoolFromTaskInput'.
##[debug]Exporting function 'Get-DomainNameFromUrl'.
##[debug]Exporting function 'Import-PowerAppsToolsPowerShellModule'.
##[debug]Exporting function 'Get-InstalledNuGetPackageRootPath'.
##[debug]Exporting function 'Get-OrgInfo'.
##[debug]Exporting function 'Wait-CrmOperation'.
##[debug]Exporting function 'Wait-EnvironmentAvailability'.
##[debug]Exporting function 'Invoke-SolutionPackager'.
##[debug]Importing function 'Get-BoolFromTaskInput'.
##[debug]Importing function 'Get-DomainNameFromUrl'.
##[debug]Importing function 'Get-InstalledNuGetPackageRootPath'.
##[debug]Importing function 'Get-OrgInfo'.
##[debug]Importing function 'Get-PSCredentialFromServiceConnection'.
##[debug]Importing function 'Get-ServiceConnection'.
##[debug]Importing function 'Get-ServicePrincipalInfoFromServiceConnection'.
##[debug]Importing function 'Import-PowerAppsToolsPowerShellModule'.
##[debug]Importing function 'Invoke-SolutionPackager'.
##[debug]Importing function 'Wait-CrmOperation'.
##[debug]Importing function 'Wait-EnvironmentAvailability'.
##[debug]Loading module from path 'D:\a\_tasks\PowerAppsImportSolution_9f15c5c5-3882-4d37-af7d-8a42a406002a\0.1.2\Get-ParameterValue.ps1'.
##[debug]Dot-sourcing the script file 'D:\a\_tasks\PowerAppsImportSolution_9f15c5c5-3882-4d37-af7d-8a42a406002a\0.1.2\Get-ParameterValue.ps1'.
##[debug]Attempting to get env variable: Env:\PowerAppsTools_Microsoft_Xrm_WebApi_PowerShell
##[debug]Importing PowerAppsTools PowerShell Module: D:\a\_tasks\PowerAppsToolInstaller_70e9ed60-670f-11e9-be16-a150d2ff01e4\0.1.2\ps_modules
##[debug]PSModulePath: C:\Users\VssAdministrator\Documents\WindowsPowerShell\Modules;C:\Program Files\WindowsPowerShell\Modules;C:\windows\system32\WindowsPowerShell\v1.0\Modules;C:\Program Files\Microsoft SQL Server\130\Tools\PowerShell\Modules\;D:\a\_tasks\PowerAppsToolInstaller_70e9ed60-670f-11e9-be16-a150d2ff01e4\0.1.2\ps_modules
##[debug]Loading module from path 'D:\a\_tasks\PowerAppsToolInstaller_70e9ed60-670f-11e9-be16-a150d2ff01e4\0.1.2\ps_modules\Microsoft.Xrm.WebApi.PowerShell\Microsoft.Xrm.WebApi.PowerShell.dll'.
##[debug]Importing cmdlet 'Export-Solution'.
##[debug]Importing cmdlet 'Import-Solution'.
##[debug]Importing cmdlet 'Publish-AllCustomizations'.
##[debug]Importing cmdlet 'Set-SolutionVersion'.
##[debug]INPUT_POWERAPPSENVIRONMENT: '6b719de5-64ec-41fe-bc8e-4ff8c0387972'
##[debug]INPUT_SOLUTIONINPUTFILE: 'd:\a\1\a\DevOPSPOC.zip'
##[debug]INPUT_CONVERTTOMANAGED: 'false'
##[debug] Converted to bool: False
##[debug]INPUT_HOLDINGSOLUTION: 'false'
##[debug] Converted to bool: False
##[debug]INPUT_OVERWRITEUNMANAGEDCUSTOMIZATIONS: 'false'
##[debug] Converted to bool: False
##[debug]INPUT_PUBLISHWORKFLOWS: 'false'
##[debug] Converted to bool: False
##[debug]INPUT_SKIPPRODUCTUPDATEDEPENDENCIES: 'false'
##[debug] Converted to bool: False
##[debug]ENDPOINT_AUTH_6b719de5-64ec-41fe-bc8e-4ff8c0387972: '********'
##[debug]ENDPOINT_DATA_6b719de5-64ec-41fe-bc8e-4ff8c0387972: '{}'
##[debug]Leaving D:\a\_tasks\PowerAppsImportSolution_9f15c5c5-3882-4d37-af7d-8a42a406002a\0.1.2\ImportSolution.ps1.
##[debug]Caught exception from task script.
##[debug]Error record:
##[debug]Import-Solution : The size necessary to buffer the XML content exceeded the buffer quota.
##[debug]At D:\a\_tasks\PowerAppsImportSolution_9f15c5c5-3882-4d37-af7d-8a42a406002a\0.1.2\ImportSolution.ps1:23 char:19
##[debug]+ ... $output = Import-Solution -ApiUrl $EnvironmentURL -Credential $PSCr ...
##[debug]+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
##[debug] + CategoryInfo : NotSpecified: (:) [Import-Solution], QuotaExceededException
##[debug] + FullyQualifiedErrorId : System.ServiceModel.QuotaExceededException,Microsoft.Xrm.WebApi.PowerShell.ImportSolutio n
##[debug]
##[debug]Script stack trace:
##[debug]at Invoke-ImportSolution<Process>, D:\a\_tasks\PowerAppsImportSolution_9f15c5c5-3882-4d37-af7d-8a42a406002a\0.1.2\ImportSolution.ps1: line 23
##[debug]at <ScriptBlock>, D:\a\_tasks\PowerAppsImportSolution_9f15c5c5-3882-4d37-af7d-8a42a406002a\0.1.2\ImportSolution.ps1: line 56
##[debug]at <ScriptBlock>, <No file>: line 1
##[debug]at <ScriptBlock>, <No file>: line 22
##[debug]at <ScriptBlock>, <No file>: line 18
##[debug]at <ScriptBlock>, <No file>: line 1
##[debug]Exception:
##[debug]System.ServiceModel.QuotaExceededException: The size necessary to buffer the XML content exceeded the buffer quota.
##[debug]
##[debug]Server stack trace:
##[debug] at System.Runtime.BufferedOutputStream.WriteCore(Byte[] buffer, Int32 offset, Int32 size)
##[debug] at System.Xml.XmlBinaryNodeWriter.FlushBuffer()
##[debug] at System.Xml.XmlStreamNodeWriter.UnsafeWriteUTF8Chars(Char* chars, Int32 charCount)
##[debug] at System.Xml.XmlBinaryNodeWriter.UnsafeWriteText(Char* chars, Int32 charCount)
##[debug] at System.Xml.XmlBinaryNodeWriter.WriteText(Char[] chars, Int32 offset, Int32 count)
##[debug] at System.Xml.XmlBaseWriter.WriteChars(Char[] chars, Int32 offset, Int32 count)
##[debug] at System.Xml.XmlBinaryWriter.WriteTextNode(XmlDictionaryReader reader, Boolean attribute)
##[debug] at System.Xml.XmlDictionaryWriter.WriteNode(XmlDictionaryReader reader, Boolean defattr)
##[debug] at System.ServiceModel.Channels.ReceivedFault.CreateFault11(XmlDictionaryReader reader, Int32 maxBufferSize)
##[debug] at System.ServiceModel.Channels.MessageFault.CreateFault(Message message, Int32 maxBufferSize)
##[debug] at System.ServiceModel.Channels.ServiceChannel.HandleReply(ProxyOperationRuntime operation, ProxyRpc& rpc)
##[debug] at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs, TimeSpan timeout)
##[debug] at System.ServiceModel.Channels.ServiceChannelProxy.InvokeService(IMethodCallMessage methodCall, ProxyOperationRuntime operation)
##[debug] at System.ServiceModel.Channels.ServiceChannelProxy.Invoke(IMessage message)
##[debug]
##[debug]Exception rethrown at [0]:
##[debug] at Microsoft.Xrm.Tooling.Connector.CrmServiceClient.Execute(OrganizationRequest request)
##[debug] at Microsoft.Xrm.WebApi.PowerShell.ImportSolution.ProcessRecord() in D:\a\1\s\source\Microsoft.Xrm.WebApi.PowerShell\cmdlet\ImportSolution.cs:line 55
##[debug] at System.Management.Automation.CommandProcessor.ProcessRecord()
##[error]The size necessary to buffer the XML content exceeded the buffer quota.
##[debug]Processed: ##vso[task.logissue type=error]The size necessary to buffer the XML content exceeded the buffer quota.
##[debug]Processed: ##vso[task.complete result=Failed]
##[section]Finishing: PowerApps Import Solution 1