Bump from .NET 6 Android Preview 9 to 14.

Author: jpobst

azure-pipelines.yml

@@ -12,6 +12,7 @@ variables:
   DotNetVersion: 6.0.200
   DotNet6Source: https://aka.ms/dotnet6/nuget/index.json
   NuGetOrgSource: https://api.nuget.org/v3/index.json
+  XamarinDotNetWorkloadSource: https://aka.ms/dotnet/maui/preview.14.json
   LegacyXamarinAndroidPkg: https://aka.ms/xamarin-android-commercial-d17-0-macos
   LegacyXamarinAndroidVsix: https://aka.ms/xamarin-android-commercial-d17-1-windows
   BUILD_NUMBER: $(Build.BuildNumber)
@@ -48,7 +49,7 @@ jobs:
           inputs:
             version: $(DotNetVersion)
         - pwsh: |
-            dotnet workload update --verbosity diag --from-rollback-file workload.json --source $(Dotnet6Source) --source $(NuGetOrgSource)
+            dotnet workload update --verbosity diag --from-rollback-file $(XamarinDotNetWorkloadSource) --source $(Dotnet6Source) --source $(NuGetOrgSource)
             dotnet workload install android --verbosity diag --skip-manifest-update --source $(Dotnet6Source) --source $(NuGetOrgSource)
         - task: JavaToolInstaller@0
           inputs: