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

========

https://hg.mozilla.org/integration/gaia-central/rev/5958b9c151b0
Author: Dominic Kuo <dkuo@mozilla.com>
Desc: Merge pull request #16871 from dominickuo/revert-bug-973156

Revert "Bug 973156 - [Music] Send mozinterruptbegin and mozinterruptend to media playback widget for displaying the correct play status"

========

https://hg.mozilla.org/integration/gaia-central/rev/ef922377795a
Author: Dominic Kuo <dkuo@mozilla.com>
Desc: Revert "Bug 973156 - [Music] Send mozinterruptbegin and mozinterruptend to media playback widget for displaying the correct play status"

This reverts commit 0682e21ae9c7406828ad013c9238e4aa1fe84fe1.
Bumping manifests a=b2g-bump