Bumping gaia.json for 4 gaia revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-central/rev/54fc56b06f2c
Author: EragonJ <eragonj@eragonj.me>
Desc: Merge pull request #15405 from EragonJ/bug-951337-another-try

Bug 951337 - SIM PIN dialog not showing up on bootup

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https://hg.mozilla.org/integration/gaia-central/rev/5e2426987675
Author: EragonJ <eragonj@eragonj.me>
Desc: Bug 951337 - SIM PIN dialog not showing up on bootup

- add test
- delay init sim_lock

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https://hg.mozilla.org/integration/gaia-central/rev/3bfe9b20e0ad
Author: Yoshi Huang <allstars.chh@mozilla.com>
Desc: Merge pull request #15531 from svic/Bug_960790

Bug 960790: Fix P2P presence discovery handling.

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https://hg.mozilla.org/integration/gaia-central/rev/7b41208bf3af
Author: Garner Lee <garner.lee@telekom.com>
Desc: Bug 960790: Fix P2P presence discovery handling.
Bumping manifests a=b2g-bump