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

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https://hg.mozilla.org/integration/gaia-central/rev/bf6ec5575daf
Author: EragonJ <eragonj@eragonj.me>
Desc: Merge pull request #17106 from EragonJ/bug-975240

Bug 975240 - [DSDS][FTE] SIM 1 or SIM 2 PIN unlock page will still show ...

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https://hg.mozilla.org/integration/gaia-central/rev/53c5028aff7c
Author: EragonJ <eragonj@eragonj.me>
Desc: Bug 975240 - [DSDS][FTE] SIM 1 or SIM 2 PIN unlock page will still show first

- add event listener for this
- add unit tests
Bumping manifests a=b2g-bump