Adapt the PipelineHandler::acquireMediaDevice() support function to return a shared pointer instead of the underlying raw pointer. Propagate this update to all pipeline handlers that use the MediaDevice and store a std::shared_ptr<MediaDevice> accordingly. This is required to support media devices that are potentially shared among multiple pipeline handlers, like a dewarper implemented as v4l2 m2m device. Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Signed-off-by: Paul Elder <paul.elder@ideasonboard.com> Signed-off-by: Stefan Klug <stefan.klug@ideasonboard.com> Reviewed-by: Isaac Scott <isaac.scott@ideasonboard.com>