chore: make owlbot check required (#201)

* chore: make owlbot check required * Update sync-repo-settings.yaml

Author: Neenu1995

.github/sync-repo-settings.yaml

@@ -16,6 +16,7 @@ branchProtectionRules:
  - units (11)
  - 'Kokoro - Test: Integration'
  - cla/google
+ - OwlBot Post Processor
  - pattern: java7
  isAdminEnforced: true
  requiredApprovingReviewCount: 1
@@ -31,6 +32,7 @@ branchProtectionRules:
  - units (11)
  - 'Kokoro - Test: Integration'
  - cla/google
+ - OwlBot Post Processor
 permissionRules:
  - team: yoshi-admins
  permission: admin