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

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https://hg.mozilla.org/integration/gaia-central/rev/0d281f0e70ba
Author: Timothy Guan-tin Chien <timdream@gmail.com>
Desc: Merge pull request #17709 from timdream/mock-event-target

Bug 987533 - [keyboard refactor] breakdown MockEventTarget, MockInputMethod, and MockInputContext from input_field_test.js, r=janjongboom

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https://hg.mozilla.org/integration/gaia-central/rev/4ee76db5ac4f
Author: Timothy Guan-tin Chien <timdream@gmail.com>
Desc: Bug 987533 -  MockEventTarget extracted from MockDOMRequest, and MockInputMethod + tests
Bumping manifests a=b2g-bump