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

========

https://hg.mozilla.org/integration/gaia-central/rev/c600a2871b21
Author: Francisco Jordano <arcturus@ardeenelinfierno.com>
Desc: Merge pull request #20368 from arcturus/bug-1023908

Bug 1023908 - [Contacts] Disable interminent integration test r=rik

========

https://hg.mozilla.org/integration/gaia-central/rev/9db605e46a0e
Author: Francisco Jordano <arcturus@ardeenelinfierno.com>
Desc: Bug 1023908 - [Contacts] Disable interminent integration test

========

https://hg.mozilla.org/integration/gaia-central/rev/88fa6799f71d
Author: Cristian Rodriguez <crdlc@tid.es>
Desc: Merge pull request #20234 from crdlc/bug-1022390

Bug 1022390 - [Vertical] Cancel download of apps

========

https://hg.mozilla.org/integration/gaia-central/rev/7144e5a59a2b
Author: crdlc <crdlc@tid.es>
Desc: Bug 1022390 - [Vertical] Cancel download of apps
Bumping manifests a=b2g-bump