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

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https://hg.mozilla.org/integration/gaia-central/rev/b2849bce85ef
Author: steveck-chung <schung@mozilla.com>
Desc: Merge pull request #17066 from steveck-chung/message-image-downsample

Bug 949779 - Modify the SMS app to use the new downsample-and-decode image feature when resizing images. r=julienw

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https://hg.mozilla.org/integration/gaia-central/rev/cf80aebd5ca3
Author: Steve Chung <schung@mozilla.com>
Desc: Bug 949779 - Modify the SMS app to use the new downsample-and-decode image feature when resizing images
Bumping manifests a=b2g-bump