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

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https://hg.mozilla.org/integration/gaia-central/rev/b77cf5f403df
Author: viorelaioia <viorela.ioia@softvision.ro>
Desc: Merge pull request #26295 from bebef1987/test_ring

Bug 1097085 - Write test Verify that the Ringer Tone can be changed

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https://hg.mozilla.org/integration/gaia-central/rev/71cd2652126c
Author: bebef1987 <florin.strugariu@softvision.ro>
Desc: Bug 1097085 - Write test Verify that the Ringer Tone can be changed
Bumping manifests a=b2g-bump