Enable jobs for mwext-BookManagerv2

Created in I0541d9470. Pushed to Jenkins API:
- mwext-BookManagerv2-merge
- mwext-BookManagerv2-jslint
- mwext-BookManagerv2-lint

Bug: 51391
Change-Id: Ia53d412b029205b0a9074cf6af729b1619afa3e4