Fix some android gn configuration

Fix file missing due to sources_assignment_filter.

Fix some use_openmax config (Depends on http://crrev.com/568363002).

BUG=359249
TBR=eseidel

Review URL: https://codereview.chromium.org/561173006

git-svn-id: svn://svn.chromium.org/blink/trunk@182119 bbb929c8-8fbe-4397-9dbb-9b2b20218538