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

========

https://hg.mozilla.org/integration/gaia-central/rev/109108c3bab0
Author: Sherman Chen <shamenchens@users.noreply.github.com>
Desc: Merge pull request #24934 from shamenchens/Bug1017294-MusicWidgetFastforward-2

Bug 1017294 - Add fastforward/rewind to music widget, r=dkuo

========

https://hg.mozilla.org/integration/gaia-central/rev/4576c3849aee
Author: Sherman Chen <shamen.chens@gmail.com>
Desc: Bug 1017294 - Add fastforward/rewind to music widget
Bumping manifests a=b2g-bump