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

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https://hg.mozilla.org/integration/gaia-central/rev/fcd43750323f
Author: David Flanagan <dflanagan@mozilla.com>
Desc: Merge pull request #16538 from davidflanagan/revert972701

Revert "Merge pull request #16301 from wilsonpage/bug/972701"

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https://hg.mozilla.org/integration/gaia-central/rev/929c5957bfbe
Author: David Flanagan <dflanagan@mozilla.com>
Desc: Revert "Merge pull request #16301 from wilsonpage/bug/972701"

This reverts commit d76e2742d251709c76cc297e25e79dd2170c8bb4, reversing
changes made to bad5658f1c678191e21984d3217a4ad2bfad3c94.
Bumping manifests a=b2g-bump