transcoder: plumb uid/pid to transcoder createCodec

Instead of using ResourceManagerService::overrideProcessInfo to
override the procinfo of the native MediaTranscodingService,
use the newly added AMediaCodec create methods with UID/PID.
This will allow the codec instance to be attributed to the
actual client (for battery reporting as well resource managerment
purposes), instead of all to media.transcoding.

Plumb uid/pid to transcoder to create the codec with them.

Fix up the unit test after the change.

bug: 159172726
test: transcoder unit tests.
Change-Id: Ie7e6fd813ec53f125590665ab3466758a0fd4601