Bumping gaia.json for 4 gaia revision(s) a=gaia-bump

========

https://hg.mozilla.org/integration/gaia-central/rev/dc502a74e9e5
Author: Yuren Ju <yurenju@gmail.com>
Desc: Merge pull request #21728 from yurenju/settings-git-commit-win

Bug 1036821 - git commit hash isn't wrote to settings/resources/gaia_commit.txt on Windows r=@cctuan

========

https://hg.mozilla.org/integration/gaia-central/rev/8c60421e42f9
Author: Yuren Ju <yurenju@gmail.com>
Desc: Bug 1036821 - git commit hash isn't wrote to settings/resources/gaia_commit.txt on Windows

========

https://hg.mozilla.org/integration/gaia-central/rev/9ffcdd34817f
Author: Kyle Machulis <kyle@nonpolynomial.com>
Desc: Merge pull request #21557 from qdot/1031369-tutorial-sim-pin-upgrade

Bug 1031369 - Show System SIM PIN dialog on upgrade after tutorial

========

https://hg.mozilla.org/integration/gaia-central/rev/0653d4ac4a64
Author: Kyle Machulis <kyle@nonpolynomial.com>
Desc: Bug 1031369 - Show System SIM PIN dialog on upgrade after tutorial
Bumping manifests a=b2g-bump