Upgrade recommended version of buildifier to 2.2.1
Upgrade recommended version of buildifier to 2.2.1

There are no formatting changes from the currently used version.

Change-Id: Ie5a4ee9b554153a757e4152ea4ea12e1f23acb2b

WANdisco/gerrit,GerritCodeReview/gerrit,WANdisco/gerrit,GerritCodeReview/gerrit,WANdisco/gerrit,WANdisco/gerrit,GerritCodeReview/gerrit,GerritCodeReview/gerrit,WANdisco/gerrit,GerritCodeReview/gerrit,GerritCodeReview/gerrit,WANdisco/gerrit,GerritCodeReview/gerrit,GerritCodeReview/gerrit,WANdisco/gerrit