Fix gtest breaking B2G build.

Port from this patch:
https://github.com/past/b2g-manifest/commit/5b090e3220ea9d1d2c72663f749fae1e7f56fba3
Merge pull request #108 from josteink/master

Bug 923032 - Fix gtest breaking Galaxy Nexus B2G build.
Add missing jhead dependency.
Merge pull request #113 from josteink/master

Bug 926609 - Add missing jhead dependency.
Add manifest for flo (Nexus 7 2013)

Signed-off-by: Vojtech Bocek <vbocek@gmail.com>
Merge pull request #114 from Tasssadar/master

Add manifest for flo (Nexus 7 2013)
use local aosp mirror

Change-Id: I9d43700cff3b1678830adf8c2906748424f17138