Upload manifest.json (#49528)

Author: wtgodbe

.azure/pipelines/jobs/default-build.yml

@@ -144,6 +144,13 @@ jobs:
     - powershell: eng\scripts\KillProcesses.ps1
       displayName: Kill processes
       condition: always()
+  - ${{ if and(eq(variables['System.TeamProject'], 'internal'), eq(parameters.agentOs, 'Windows')) }}:
+    - powershell: |
+        $snapshot = (Get-Content ./build/manifest.dummy.json | ConvertFrom-Json)
+        $snapshot.builds[0].commit='$(Build.SourceVersion)'
+        New-Item ./artifacts/manifest.json
+        $snapshot | ConvertTo-Json -depth 10 | Out-File "./artifacts/manifest.json"
+      displayName: Create manifest.json
   - ${{ if ne(parameters.variables.PB_SKIPTESTS, 'true') }}:
     - task: PublishTestResults@2
       displayName: Publish test results

build/manifest.dummy.json

@@ -0,0 +1,9 @@
+{
+    "builds": [
+        {
+            "repo": "https://dev.azure.com/dnceng/internal/_git/dotnet-aspnetcore",
+            "commit": "DUMMY",
+            "branch": "refs/heads/internal/release/2.1"
+        }  
+    ]
+}