set isFullMatrix to true for all PRs

Author: John Salem

eng/pipelines/common/variables.yml

@@ -2,7 +2,7 @@ variables:
 - name: isOfficialBuild
   value: ${{ and(ne(variables['System.TeamProject'], 'public'), ne(variables['Build.Reason'], 'PullRequest')) }}
 - name: isFullMatrix
-  value: ${{ and(eq(variables['System.TeamProject'], 'public'), ne(variables['Build.Reason'], 'PullRequest')) }}
+  value: true
 - name: debugOnPrReleaseOnRolling
   ${{ if ne(variables['Build.Reason'], 'PullRequest') }}:
     value: Release