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

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https://hg.mozilla.org/integration/gaia-central/rev/d48fa23f94b5
Author: Greg Weng <snowmantw@gmail.com>
Desc: Merge pull request #21171 from snowmantw/issue1024951

Bug 1024951 - [NFC] Dialer screenshot shows on shrink UI ...

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https://hg.mozilla.org/integration/gaia-central/rev/9c728d4c9054
Author: Greg Weng <snowmantw@gmail.com>
Desc: Bug 1024951 - [NFC] Dialer screenshot shows on shrink UI when try to share contact if dialer is running on the background
Bumping manifests a=b2g-bump