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

========

https://hg.mozilla.org/integration/gaia-central/rev/15a76be03f01
Author: Timothy Guan-tin Chien <timdream@gmail.com>
Desc: Merge pull request #22470 from timdream/keyboard-latin-new-uint8

Bug 1048135 - Add new keyword on Uint8Array instance creation, r=rudyl

========

https://hg.mozilla.org/integration/gaia-central/rev/d5235d201196
Author: Timothy Guan-tin Chien <timdream@gmail.com>
Desc: Bug 1048135 - Add new keyword on Uint8Array instance creation

========

https://hg.mozilla.org/integration/gaia-central/rev/17de4b2606e5
Author: Timothy Guan-tin Chien <timdream@gmail.com>
Desc: Merge pull request #22474 from mozilla-b2g/revert-22461-keyboard-vwrapper-css

Revert "Bug 1048025 - Set pointer-events: none to visual-wrapper"

========

https://hg.mozilla.org/integration/gaia-central/rev/0ceb9239e8b2
Author: Timothy Guan-tin Chien <timdream@gmail.com>
Desc: Revert "Bug 1048025 - Set pointer-events: none to visual-wrapper +shepherd"
Bumping manifests a=b2g-bump