Merge branch 'stable-3.10' into stable-3.11

* stable-3.10:
  Do not lock refs when not executing a fetch
  Allow locking refs whilst filtering for fetch requests
  Remove unused Transport in FetchOneTest
  Avoid mocking ReplicationFetchFilter
  Remove redundant public modifier in ReplicationFetchFilter
  Record replication metrics for retrying tasks

Change-Id: I4bbbbd665e155205f691041ac0140b68ec041df6