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

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https://hg.mozilla.org/integration/gaia-1_4/rev/2b1c8eae49e8
Author: Ryan VanderMeulen <rvandermeulen@mozilla.com>
Desc: Merge pull request #18818 from PinZhang/pzhang/bug997064-v1.4

Bug 997064: Do not call navigator.mozFMRadio from system app.

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https://hg.mozilla.org/integration/gaia-1_4/rev/7bb120507be8
Author: Pin Zhang <pzhang@mozilla.com>
Desc: Bug 997064: Do not call navigator.mozFMRadio from system app.
Bumping manifests a=b2g-bump