QCamera and QMediaPlayer are likely to wait for valid
surface to be passed to the renderer control before startup, so after
player->setVideoOutput(nullSurface)
player will not start playback.
If the renderer control was already requested before for valid
surface it should be released when the null surface is assigned.
Change-Id: I3f78f2d82e61fae5f305874874c0ffbc4cb7dc1d
Reviewed-by: Jonas Rabbe <jonas.rabbe@nokia.com>
e2eaa283fb