chore: update permissions of autoconfig generation job (#3677)

Based on https://togithub.com/googleapis/google-cloud-java/pull/11498

Author: diegomarquezp

.github/workflows/generateAutoConfigs.yaml

@@ -19,6 +19,9 @@ jobs:
     # log information required for manually triggering workflow and exit with error to block PR
     if: ${{ (github.event_name == 'workflow_dispatch') || startsWith(github.head_ref, 'renovate/main-gcp-libraries-bom.version') || startsWith(github.head_ref, 'dependabot/maven/com.google.cloud-libraries-bom') }}
     runs-on: ubuntu-latest
+    permissions:
+      contents: write
+      pull-requests: write
     env:
       GITHUB_TOKEN: ${{ secrets.CLOUD_JAVA_BOT_GITHUB_TOKEN }}
     steps:
@@ -148,7 +151,7 @@ jobs:
             git stash pop
             git add ./spring-cloud-previews
             git commit -m "chore: update starter modules in spring-cloud-previews"
-            git push https://github.com/${{ github.event.inputs.forked_repo }}.git HEAD:${{ github.event.inputs.branch_name }}
+            git push https://${{ secrets.CLOUD_JAVA_BOT_GITHUB_TOKEN }}@github.com/${{ github.event.inputs.forked_repo }}.git HEAD:${{ github.event.inputs.branch_name }}
           else
             git remote remove origin
             git remote add origin https://${{ secrets.CLOUD_JAVA_BOT_GITHUB_TOKEN }}@github.com/GoogleCloudPlatform/spring-cloud-gcp.git