Bumping gaia.json for 4 gaia-central revision(s) a=gaia-bump

========

https://hg.mozilla.org/integration/gaia-central/rev/b6654a95fe1c
Author: Trif Andrei-Alin <trifandreialin@gmail.com>
Desc: Merge pull request #14827 from bobsilverberg/persona_frames

Bug 937336 - Remove where possible explicit frame switching

========

https://hg.mozilla.org/integration/gaia-central/rev/35fc70e3442c
Author: Bob Silverberg <bob.silverberg@gmail.com>
Desc: Bug 937336 - Remove where possible explicit frame switching

Change to Persona test

========

https://hg.mozilla.org/integration/gaia-central/rev/7b7dde8a85e7
Author: Trif Andrei-Alin <trifandreialin@gmail.com>
Desc: Merge pull request #14826 from bobsilverberg/kb_frames

Bug 937336 - Remove where possible explicit frame switching

========

https://hg.mozilla.org/integration/gaia-central/rev/f1ed0aa660bb
Author: Bob Silverberg <bob.silverberg@gmail.com>
Desc: Bug 937336 - Remove where possible explicit frame switching

Remove explicit frame switching from keyboard tests