Camera2: Tests -- Fork each test before executing it

Use CAMERA2_TEST_FORKING_DISABLED=1 environment variable to override this
behavior (e.g. when wanting to attach gdb to the test app).

Change-Id: Ib639885bdb827fc2415c878cbcb1b2d84dff687b
diff --git a/tests/camera2/camera2_utils.h b/tests/camera2/camera2_utils.h
index c938ee7..757044b 100644
--- a/tests/camera2/camera2_utils.h
+++ b/tests/camera2/camera2_utils.h
@@ -14,6 +14,9 @@
  * limitations under the License.
  */
 
+#ifndef __ANDROID_HAL_CAMERA2_TESTS_UTILS__
+#define __ANDROID_HAL_CAMERA2_TESTS_UTILS__
+
 // Utility classes for camera2 HAL testing
 
 #include <system/camera_metadata.h>
@@ -243,3 +246,5 @@
 }
 }
 }
+
+#endif