chore: remove java7 units check from required checks in master (#504)

Author: Neenu1995

.github/sync-repo-settings.yaml

@@ -34,7 +34,6 @@ branchProtectionRules:
   - "linkage-monitor"
   - "lint"
   - "clirr"
-  - "units (7)"
   - "units (8)"
   - "units (11)"
   - "Kokoro - Test: Integration"