When developer options switch is off, a user including guest user
can still configure media transcoding settings via slices.
Bug: 244569778
Test: manual
Change-Id: I3d70045c2498e683bf615cbe521e2f98d50b7eec
This is to provide users with control over whether to disable
transcoding cache or not.
By default we keep the transcoding cache enabled.
The controller resides within the Media transcoding settings under
Developer Options.
Test: Manual. Unit tests added.
Bug: 185246580
Change-Id: I5cc85e4a254c87b5c84c32a303e8294c918748c2