Bumping gaia.json for 3 gaia revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-central/rev/a6c00d7fb53d
Author: Francisco Jordano <fjordano@mozilla.com>
Desc: Revert "Bug 1017333 - Clear notifications when we open the call log"

This reverts commit 9cdc9343f7eec62182d2cc25c022fc8947ddc037.

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https://hg.mozilla.org/integration/gaia-central/rev/4f8c8b573a35
Author: Wilson Page <wilsonpage@me.com>
Desc: Merge pull request #20355 from wilsonpage/1021492

Last Comment Bug 1021492 - [Camera] Use bower to manage dependencies in the lib/vendor directory

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https://hg.mozilla.org/integration/gaia-central/rev/e74173ae39fd
Author: Wilson Page <wilsonpage@me.com>
Desc: Bug 1021492 - [Camera] Use bower to manage dependencies in the lib/vendor directory
Bumping manifests a=b2g-bump