Bumping gaia.json for 4 gaia revision(s) a=gaia-bump

========

https://hg.mozilla.org/integration/gaia-central/rev/ee24e7b95fbd
Author: Ben Tian <btian@mozilla.com>
Desc: Merge pull request #18674 from bentian/bug-997578

Bug 997578 - Answer incoming call after hanging up active call, r=etienne, a=1.4+

========

https://hg.mozilla.org/integration/gaia-central/rev/5b8cc0be2994
Author: Ben Tian <btian@mozilla.com>
Desc: Bug 997578 - Answer incoming call after hanging up active call, a=1.4+

========

https://hg.mozilla.org/integration/gaia-central/rev/43ec83565718
Author: Etienne Segonzac <etienne@segonzac.info>
Desc: Merge pull request #18542 from etiennesegonzac/bug-992081-edge-overlay

Bug 992081 - Adding an indentification overlay while swiping sheets r=alive

========

https://hg.mozilla.org/integration/gaia-central/rev/1f9d7d72475d
Author: Etienne Segonzac <etienne@segonzac.info>
Desc: Bug 992081 - Adding an indentification overlay while swiping sheets and hardening the edge gesture.
Bumping manifests a=b2g-bump