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

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https://hg.mozilla.org/integration/gaia-central/rev/9bf9368a1110
Author: George <georgeiscoming@gmail.com>
Desc: Merge pull request #12155 from cctuan/911673

Bug 911673 - [system] use 'scroll from device side to screen'(scroll up) gesture to back to homescreen

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https://hg.mozilla.org/integration/gaia-central/rev/483951ba1552
Author: cctuan <georgeiscoming@gmail.com>
Desc: Bug 911673 use 'scroll from device side to screen'(scroll up) gesture to back to homescreen