kitakami-common: media: Give /dev/msm_vidc_* camera group and video_device label

 * The mediacodec (or android.hardware.media.omx@1.0-service)
    services do not have the audio groups but camera,
    therefore update the group to avoid access denial

 * Resolve denials with public/mediacodec.te:
    allow mediacodec video_device:chr_file rw_file_perms;

Change-Id: I1da83eaab461ec7a98753009684ee3dca951b791