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/066f020ddb93
Author: Zac <zcampbell@mozilla.com>
Desc: Merge pull request #13332 from bobsilverberg/v1.2manifest

Bug 934230 - [v1.2] Update all manifest files to be in line with master

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https://hg.mozilla.org/integration/gaia-1_2/rev/0f858679f8be
Author: Zac Campbell <zcampbell@mozilla.com>
Desc: Bug 934230 - [v1.2] Update all manifest files to be in line with master