Add feature flag to change the CDM version to 18.0.2

[ Merge of http://go/wvgerrit/191139 ]

Adding an initial flag that include identifiable differences when
the feature is enabled or disabled.

This is the same commit as ag/25837302. It was reverted due to
memory size issues. A follow on CL will address that issue to
ease review.

Bug: 311951236
Test: WVTS tests
Change-Id: I995fb8f4158b3529c2d19a2ee5fd8beec0019f7c

libwvdrmengine/mediacrypto/test/Android.mk

@@ -42,6 +42,7 @@ LOCAL_SHARED_LIBRARIES := \
   libprotobuf-cpp-lite \
   libutils \
   libwvaidl \
+  wv_media_drm_flags_c_lib \
 
 LOCAL_HEADER_LIBRARIES := \
   libstagefright_headers \