Don't use the official manifest on stabilize-5116.88.B.

This branch has a working regular manifest, but the official
manifest is not set up yet, nor needed. Switch over.

BUG=none
TEST=cbuildbot_config_unittest.py

Change-Id: I70308afd63f14e0eee770e57ea31dddcb0e83a46
Previous-Reviewed-on: https://chromium-review.googlesource.com/188647
(cherry picked from commit 0488c04afba00f369c3b04604abab6a216593397)
Reviewed-on: https://chromium-review.googlesource.com/189615
Reviewed-by: Dharani Govindan <dharani@chromium.org>
Tested-by: Dharani Govindan <dharani@chromium.org>
1 file changed