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

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https://hg.mozilla.org/integration/gaia-central/rev/714821e19c13
Author: Greg Weng <snowmantw@gmail.com>
Desc: Merge pull request #20542 from snowmantw/issue1025723

Bug 1025723 - [LockScreen][System] Change the old locking events with new window events

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https://hg.mozilla.org/integration/gaia-central/rev/d6cc2c559b2b
Author: Greg Weng <snowmantw@gmail.com>
Desc: Bug 1025723 - [LockScreen][System] Change the old locking events with new window events
Bumping manifests a=b2g-bump