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

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https://hg.mozilla.org/integration/gaia-central/rev/d7b307038d9b
Author: Etienne Segonzac <etienne@segonzac.info>
Desc: Merge pull request #15352 from etiennesegonzac/bug-883080-exit-edit-missed-calls

Bug 883080 - Switching from all calls to missed calls should exit the call log edit mode. r=rik

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https://hg.mozilla.org/integration/gaia-central/rev/534e7ac0f8f7
Author: Etienne Segonzac <etienne@segonzac.info>
Desc: Bug 883080 - Switching from all calls to missed calls should exit the call log edit mode.