Bumping gaia.json for 2 gaia-1_3 revision(s) a=gaia-bump

========

https://hg.mozilla.org/integration/gaia-1_3/rev/317f40f2a088
Author: David Flanagan <dflanagan@mozilla.com>
Desc: Merge pull request #15085 from davidflanagan/bug939679v1.3

Merge pull request #14912 from davidflanagan/bug939679

========

https://hg.mozilla.org/integration/gaia-1_3/rev/fe047da22720
Author: David Flanagan <dflanagan@mozilla.com>
Desc: Merge pull request #14912 from davidflanagan/bug939679

Bug 939679: compute the right camera preview size on HD devices r=dmarcos(cherry picked from commit 4245fb93e747d3e3cc9e50ba6fa2f084c9cb682f)