chore: update from 15 to 16 for status checks (#1752)

Author: ddelgrosso1

.github/sync-repo-settings.yaml

@@ -17,7 +17,7 @@ branchProtectionRules:
  - test (10)
  - test (12)
  - test (14)
- - test (15)
+ - test (16)
  - cla/google
  - windows
  - OwlBot Post Processor