Bumping gaia.json for 2 gaia-1_2 revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-1_2/rev/f1c792348048
Author: steveck-chung <schung@mozilla.com>
Desc: Merge pull request #13682 from steveck-chung/incoming-call-for-1.2

Bug 924736 - [Dialer] Incoming call lock screen icons css/animation fine-tune. r=etiennesegonzac,  a=timdream

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https://hg.mozilla.org/integration/gaia-1_2/rev/e43d74f64958
Author: Steve Chung <schung@mozilla.com>
Desc: Bug 924736 - [Dialer] Incoming call lock screen icons css/animation fine-tune