Update source-build CI to not arm64 leg on internal PRs

src/SourceBuild/Arcade/eng/common/templates/job/source-build-run-tarball-build.yml

@@ -78,22 +78,19 @@ jobs:
       ${{ if eq(variables['System.TeamProject'], 'internal') }}:
         ${{ parameters.poolInternalAmd64 }}
 
-- ${{ if eq(variables['System.TeamProject'], 'internal') }}:
+- ${{ if and(eq(variables['System.TeamProject'], 'internal'), ne(variables['Build.Reason'], 'PullRequest')) }}:
   - template: /src/SourceBuild/Arcade/eng/common/templates/job/source-build-build-tarball.yml
     parameters:
       architecture: arm64
       dependsOn: ${{ parameters.dependsOn }}
-      ${{ if in(variables['Build.Reason'], 'PullRequest') }}:
-        excludeSdkContentTests: true
       installerBuildResourceId: ${{ parameters.installerBuildResourceId }}
       matrix:
-        ${{ if ne(variables['Build.Reason'], 'PullRequest') }}:
-          Debian9-Offline:
-            _BootstrapPrep: true
-            _Container: ${{ parameters.debian9Arm64Container }}
-            _EnablePoison: false
-            _ExcludeOmniSharpTests: false
-            _RunOnline: false
+        Debian9-Offline:
+          _BootstrapPrep: true
+          _Container: ${{ parameters.debian9Arm64Container }}
+          _EnablePoison: false
+          _ExcludeOmniSharpTests: false
+          _RunOnline: false
       name: Build_Tarball_arm64
       pool: ${{ parameters.poolInternalArm64 }}