Upgrade bazlets to latest master to build with 3.0.0-rc1 API

Switch from snapshot to release API usage to do so.

Adapt to the removal of ReviewDB by means of removing OrmException uses.
Replace OrmException use with PermissionBackendException in
EventRestApiServletTest and ForwardedEventHandlerTest.

Adapt to ChangeIndexer's index methods no longer throwing IOException in
ForwardedIndexChangeHandlerTest.

Remove unthrown IOException from ForwardedIndexingHandlers declarations.

Change-Id: I710eaf6e2c770b10acb1d2a2160708e718fc4187
17 files changed