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

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https://hg.mozilla.org/integration/gaia-central/rev/17892a41a093
Author: Germán Toro del Valle <gtorodelvalle@gmail.com>
Desc: Merge pull request #21867 from gtorodelvalle/callscreen-bug-1024506-call-option-buttons

Bug 1024506 - While call is "connecting", "Add other call", "Keypad" and "microphone" buttons should be disabled

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https://hg.mozilla.org/integration/gaia-central/rev/64581952209f
Author: German Toro del Valle <gtorodelvalle@gmail.com>
Desc: Bug 1024506 - While call is "connecting", "Add other call", "Keypad" and "microphone" buttons should be disabled.
Bumping manifests a=b2g-bump