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

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https://hg.mozilla.org/integration/gaia-central/rev/b7c6efd07444
Author: Alive.Kuo <alegnadise@gmail.com>
Desc: Merge pull request #16061 from alivedise/bugzilla/935750/revive-dead-app-instead-destroy

Bug 935750 - Revive crashed app once got opened. r=etienne

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https://hg.mozilla.org/integration/gaia-central/rev/23ae61e91859
Author: Alive Kuo <alegnadise@gmail.com>
Desc: Bug 935750 - Implement Suspending AppWindow and Priority Manager
Bumping manifests a=b2g-bump