Camera2: Tests: Add CLI arguments for disabling forking and changing camera ID

Change-Id: I0adfda42e861d7e5a85801f7e0c3f0b3950b6e0e
diff --git a/tests/camera2/TestExtensions.h b/tests/camera2/TestExtensions.h
index 68a5e97..2af587d 100644
--- a/tests/camera2/TestExtensions.h
+++ b/tests/camera2/TestExtensions.h
@@ -18,6 +18,7 @@
 #define __ANDROID_HAL_CAMERA2_TESTS_EXTENSIONS__
 
 #include "TestForkerEventListener.h"
+#include "TestSettings.h"
 
 // Use at the beginning of each Test::SetUp() impl
 #define TEST_EXTENSION_FORKING_SET_UP                                       \
@@ -46,7 +47,8 @@
     } while(false)                                                          \
 
 // Are we running each test by forking it?
-#define TEST_EXTENSION_FORKING_ENABLED  (TestForkerEventListener::mUsingForking)
+#define TEST_EXTENSION_FORKING_ENABLED                                      \
+    (android::camera2::tests::TestSettings::ForkingEnabled())