SF: Block gpu rendering for virtual display widevine level3

In MPD3 we are using the widevine level3 for secure content
display. And this should applicable only for primary display
not for screen shot or screen recording.

CRs-Fixed: 595469
Change-Id: I99be2d81287ab746d5c4a2375c3106c59e61a8fc
Merge pull request #9 from CyanogenMod/cm-11.0

SF: Block gpu rendering for virtual display widevine level3