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

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https://hg.mozilla.org/integration/gaia-central/rev/df127b6f7858
Author: Dave Hylands <dhylands@gmail.com>
Desc: Merge pull request #25505 from dhylands/bug-1068933-ds-test

Bug 1068933 - Added a ds_enumerate_since routine to ds-test, for testing...

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https://hg.mozilla.org/integration/gaia-central/rev/270c8ffaccc0
Author: Dave Hylands <dhylands@gmail.com>
Desc: Bug 1068933 - Added a ds_enumerate_since routine to ds-test, for testing this bug.
Bumping manifests a=b2g-bump