Bumping gaia.json for 2 gaia revision(s) a=gaia-bump

========

https://hg.mozilla.org/integration/gaia-2_0/rev/872e1dc87504
Author: Etienne Segonzac <etienne@segonzac.info>
Desc: Merge pull request #22063 from etiennesegonzac/bug-1036642-2.0-uplift

bug-1036642 uplift to 2.0

========

https://hg.mozilla.org/integration/gaia-2_0/rev/baf4037ea86a
Author: Etienne Segonzac <etienne@segonzac.info>
Desc: Merge pull request #21877 from etiennesegonzac/bug-1036642

Bug 1036642 - Enable access to the rocketbar while on a call. r=21
(cherry picked from commit 946c019bd52af3de71895e8a7c54c48e58ad6bf1)

Conflicts:
	apps/system/js/home_searchbar.js
	apps/system/test/unit/rocketbar_test.js
Bumping manifests a=b2g-bump