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

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https://hg.mozilla.org/integration/gaia-1_4/rev/7aa28d336654
Author: Etienne Segonzac <etienne@segonzac.info>
Desc: Merge pull request #18217 from etiennesegonzac/bug-993807-network-initiated-mmi

Bug 993807 - Making sure the MmiManager is initialized for network initiated MMI sessions. r=rik

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https://hg.mozilla.org/integration/gaia-1_4/rev/46ed1cd7faf3
Author: Jose Antonio Olivera Ortega <josea.olivera@gmail.com>
Desc: Merge pull request #18069 from jaoo/991628

Bug 991628 - [Settings][OMA CP] Not possible to select an APN received via OMA CP message if there is already one with the same name. r=arthurcc
Bumping manifests a=b2g-bump