* stable-5.10: Prepare 5.1.17-SNAPSHOT builds JGit v5.1.16.202106041830-r BatchRefUpdate: Skip saving conflicting ref names and prefixes in memory BatchRefUpdateTest: Accurately assert RefsChangedEvent(s) fired Optimize RefDirectory.isNameConflicting() Update bazlets and bazel version Change-Id: I265425194c24fd82cbeff869ce41cbc9b73571a2