media_codecs.xml: enable & prioritize qcom omx encoders

Depends on this change:
http://server.cas-online.nl:8181/#/c/460/

Change-Id: I4a05eac80c5f046ba3ec537e25b2a0f2f1bbcec9
Merge "media_codecs.xml: enable & prioritize qcom omx encoders" into cm-10.1