Bumping gaia.json for 1 gaia-1_2 revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-1_2/rev/946a66cd12f7
Author: Fernando Campo <fernando.campo@o2.com>
Desc: Merge pull request #12710 from fcampo/ftu-doneButton-824929

Bug 824929 - [SIM screen] The Done key is always active and can be pressed before the PIN Code is introduced (r=jmcf)(cherry picked from commit 907a8656e49599d334203c22dcbdb3f98c1d7864)