Bumping gaia.json for 1 gaia revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-1_4/rev/ffa2d74a581d
Author: Michael Henretty <michael.henretty@gmail.com>
Desc: Merge pull request #17603 from mikehenrty/bug-975973-lite

Bug 975973 - [DSDS] The "data circle" icon is not made smaller for DSDS ...
(cherry picked from commit 4b6044162277ae481d26244e7441c0a16dc63e01)
Bumping manifests a=b2g-bump