Bulk Operation

HBASE-24584 Set version as 2.2.7-SNAPSHOT in branch-2.2

HBASE-24584 Add 2.2.6 to download page

HBASE-24584 Reduce the resource of TestReplicationBase

HBASE-24584 Remove the metrics assert in TestClusterRestartFailover

HBASE-24584 Turn off the balancer when test region admin api

HBASE-24584 Enlarge the wait time in TestReplicationEndpoint/TestMetaWithReplicasBasic

HBASE-24584 Speed up some unit tests

HBASE-24584 Speed up TestFromClientSide3 by reduce the table regions number

HBASE-24584 Fix the shellcheck download url

HBASE-24584 Backport part of HBASE-24079 and HBASE-24034

HBASE-24584 Backport HBASE-23956: Use less resources running tests to branch-2.2

HBASE-24584 Fix flaky test TestRaceBetweenSCPAndDTP and TestRaceBetweenSCPAndTRSP for branch-2.2

HBASE-24584 Fix flaky TestWALEntryStream

HBASE-24584 Set version to 2.2.6 in branch-2.2 for first RC of 2.2.6

HBASE-24584 Generate CHANGES.md and RELEASENOTES.md for 2.2.6