.asf.yaml details are determined

[steven lu]

For details, see https://github.com/apache/bookkeeper/pull/3453

Now Bookkeeper is using .asf.yaml (
https://cwiki.apache.org/confluence/display/INFRA/Git+-+.asf.yaml+features#Git.asf.yamlfeatures-Branchprotection
) to configure the project,
.asf.yaml details are determined

   1.

   Whether checks are enough,
   now these checks are required:

      contexts:
        - PR Validation
        - Backward compatibility tests
        - Bookie Tests
        - Build with macos on JDK 11
        - Build with windows on JDK 11
        - Client Tests
        - Compatibility Check Java11
        - Compatibility Check Java17
        - Compatibility Check Java8
        - Integration Tests
        - Remaining Tests
        - Replication Tests
        - StreamStorage Tests
        - TLS Tests

   Do we need to add others, such as: OWASP Dependency Check?
   2.

   required_approving_review_count:
   2.1) is there a need for a limit
   2.2) or is the value more reasonable, 1 or 2?