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

========

https://hg.mozilla.org/integration/gaia-central/rev/8cd6c73ef832
Author: Yuren Ju <yurenju@gmail.com>
Desc: Merge pull request #21172 from yurenju/multilocale-manifest

Bug 1007485 - manifest.webapp shoud not be localized in en-US if LOCALE_... r=@cctuan

========

https://hg.mozilla.org/integration/gaia-central/rev/848f923d00cc
Author: Yuren Ju <yurenju@gmail.com>
Desc: Bug 1007485 - manifest.webapp shoud not be localized in en-US if LOCALE_BASEDIR/en-US exists
Bumping manifests a=b2g-bump