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

========

https://hg.mozilla.org/integration/gaia-central/rev/356303b917b6
Author: Zac Campbell <zcampbell@mozilla.com>
Desc: Bug 937094 -Python Re-enable test_everything_me_search.py

========

https://hg.mozilla.org/integration/gaia-central/rev/b519f4cd9375
Author: Zac Campbell <zcampbell@mozilla.com>
Desc: Bug 937102 - Python Reenable test_sms_with_attachments.py r=me a=testonly