Set up CI with Azure Pipelines

[skip ci]

Author: davidbritch

azure-pipelines-android.yml

@@ -0,0 +1,12 @@
+pool:
+  vmImage: 'macos-latest'
+steps:
+  - script: sudo $AGENT_HOMEDIRECTORY/scripts/select-xamarin-sdk.sh 5_12_0
+    displayName: 'Select the Xamarin SDK version'
+    enabled: false
+  - task: MSBuild@1
+    displayName: Build Android samples
+    inputs:
+      solution: '**/*Droid*.csproj'
+      configuration: 'Debug'
+      msbuildArguments: '/restore /t:Build /p:ContinuousIntegrationBuild=true /p:Deterministic=false'