MediaCas: move clear key plugin to /system/lib

Non-treble process can no longer load .so from /vendor/lib.
Move the clear key plugin to /system/lib until MediaCas is converted
to treble.

bug: 37476803
Change-Id: I563b4576aeada5470355e7e168fa2c73997004d7
diff --git a/drm/mediacas/plugins/clearkey/Android.mk b/drm/mediacas/plugins/clearkey/Android.mk
index 0c2b357..8fd866c 100644
--- a/drm/mediacas/plugins/clearkey/Android.mk
+++ b/drm/mediacas/plugins/clearkey/Android.mk
@@ -28,7 +28,8 @@
 
 LOCAL_MODULE := libclearkeycasplugin
 
-LOCAL_PROPRIETARY_MODULE := true
+#TODO: move this back to /vendor/lib after conversion to treble
+#LOCAL_PROPRIETARY_MODULE := true
 LOCAL_MODULE_RELATIVE_PATH := mediacas
 
 LOCAL_SHARED_LIBRARIES := \
diff --git a/drm/mediacas/plugins/clearkey/tests/Android.mk b/drm/mediacas/plugins/clearkey/tests/Android.mk
index 5418c1d..cbf7be7 100644
--- a/drm/mediacas/plugins/clearkey/tests/Android.mk
+++ b/drm/mediacas/plugins/clearkey/tests/Android.mk
@@ -26,7 +26,7 @@
 # the plugin is not in standard library search path. Without this .so
 # loading fails at run-time (linking is okay).
 LOCAL_LDFLAGS := \
-    -Wl,--rpath,\$${ORIGIN}/../../../system/vendor/lib/mediacas -Wl,--enable-new-dtags
+    -Wl,--rpath,\$${ORIGIN}/../../../system/lib/mediacas -Wl,--enable-new-dtags
 
 LOCAL_SHARED_LIBRARIES := \
     libutils libclearkeycasplugin libstagefright_foundation libprotobuf-cpp-lite liblog
diff --git a/services/mediadrm/FactoryLoader.h b/services/mediadrm/FactoryLoader.h
index 1e03e9b..d7f1118 100644
--- a/services/mediadrm/FactoryLoader.h
+++ b/services/mediadrm/FactoryLoader.h
@@ -88,7 +88,7 @@
     }
 
     // no luck, have to search
-    String8 dirPath("/vendor/lib/mediacas");
+    String8 dirPath("/system/lib/mediacas");
     DIR* pDir = opendir(dirPath.string());
 
     if (pDir == NULL) {
@@ -123,7 +123,7 @@
 
     results->clear();
 
-    String8 dirPath("/vendor/lib/mediacas");
+    String8 dirPath("/system/lib/mediacas");
     DIR* pDir = opendir(dirPath.string());
 
     if (pDir == NULL) {