Update signing to v2 (#451)

Co-authored-by: Jonathan Dick <jodick@microsoft.com>

SignList.xml

@@ -0,0 +1,16 @@
+<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+
+  <ItemGroup>
+    <FirstParty Include="Firebase.*.dll" />
+    <FirstParty Include="Google.*.dll" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <!-- <ThirdParty Include="..." /> -->
+  </ItemGroup>
+
+  <ItemGroup>
+    <!-- <Skip Include="..." /> -->
+  </ItemGroup>
+
+</Project>

azure-pipelines.yml

@@ -8,6 +8,7 @@ resources:
       type: github
       name: xamarin/yaml-templates
       endpoint: xamarin
+      ref: refs/heads/main
     - repository: components
       type: github
       name: xamarin/XamarinComponents
@@ -27,9 +28,7 @@ jobs:
       windowsImage: ''
       xcode: '12'
   - ${{ if eq(variables['System.TeamProject'], 'devdiv') }}:
-    - template: sign-artifacts/jobs/v1.yml@internal-templates
+    - template: sign-artifacts/jobs/v2.yml@internal-templates
       parameters:
         dependsOn: [ 'build' ]
-        signTags: true
-        signMain: true
-        realSign: true
+        condition: startsWith(variables['Build.SourceBranch'], 'refs/tags/')