Bumping gaia.json for 6 gaia revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-central/rev/75b0b4bbb2c6
Author: Dominic Kuo <dkuo@mozilla.com>
Desc: Merge pull request #22505 from dominickuo/bug-1048673

Bug 1048673 - [Ringtones] stop the previews before leaving the app, r=jimporter

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https://hg.mozilla.org/integration/gaia-central/rev/84685c08882e
Author: Dominic Kuo <dkuo@mozilla.com>
Desc: Bug 1048673 - [Ringtones] stop the previews before leaving the app

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https://hg.mozilla.org/integration/gaia-central/rev/447ca18c4fbb
Author: EragonJ <eragonj@eragonj.me>
Desc: Merge pull request #22475 from EragonJ/bug-1034560-another-try

Bug 1034560 - Utility tray is closed when the airplanemode button is pre...

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https://hg.mozilla.org/integration/gaia-central/rev/97e9162ba52a
Author: EragonJ <eragonj@eragonj.me>
Desc: Bug 1034560 - Utility tray is closed when the airplanemode button is pressed

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https://hg.mozilla.org/integration/gaia-central/rev/75c747377088
Author: Rudy Lu <me@rudy.lu>
Desc: Merge pull request #22506 from RudyLu/keyboard/Bug1048682-jspinyin_unit_tests

Bug 1048682 - Fix failing jspinyin unit tests.
r=yxl.

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https://hg.mozilla.org/integration/gaia-central/rev/f32da2f1621b
Author: Rudy Lu <me@rudy.lu>
Desc:  Bug 1048682 - Fix failing jspinyin unit tests.
Bumping manifests a=b2g-bump