android: camera_device: Check capture_request validity

Make sure the 'camera3_capture_request_t *' provided to
CameraDevice::processCaptureRequest() is valid before attempting to
access it.

This patch fixes cros_camera_test:
Camera3FrameTest/Camera3InvalidRequestTest.NullOrUnconfiguredRequest/*

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>

src/android/camera_device.cpp

@@ -1398,6 +1398,11 @@ FrameBuffer *CameraDevice::createFrameBuffer(const buffer_handle_t camera3buffer
 
 int CameraDevice::processCaptureRequest(camera3_capture_request_t *camera3Request)
 {
+	if (!camera3Request) {
+		LOG(HAL, Error) << "No capture request provided";
+		return -EINVAL;
+	}
+
 	if (!camera3Request->num_output_buffers) {
 		LOG(HAL, Error) << "No output buffers provided";
 		return -EINVAL;