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

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https://hg.mozilla.org/integration/gaia-central/rev/ddb0d74e867d
Author: David Flanagan <dflanagan@mozilla.com>
Desc: Merge pull request #25957 from davidflanagan/bug1095310

Bug 1095310: correctly detect BMP files that are larger than 64kb r=justindarc

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https://hg.mozilla.org/integration/gaia-central/rev/6b53f10035b7
Author: David Flanagan <dflanagan@mozilla.com>
Desc: Bug 1095310: correctly detect BMP files that are larger than 64kb
Bumping manifests a=b2g-bump