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

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https://hg.mozilla.org/integration/gaia-1_3/rev/388d646c7527
Author: Gabriele Svelto <gsvelto@mozilla.com>
Desc: Bug 991666 - Fix removal of old API notifications when selected from the toaster r=alive

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https://hg.mozilla.org/integration/gaia-1_3/rev/30621eb4c542
Author: Anthony Ricaud <anthony@ricaud.me>
Desc: Merge pull request #14577 from Rik/stop-ringtone-power-button-890434

Bug 890434 - Impossible to silence an incoming call without rejecting it r=etienne
Conflicts:
	apps/communications/dialer/test/unit/calls_handler_test.js
Bumping manifests a=b2g-bump