Cherry pick 18.4 changes to udc-widevine-dev

Get the udc-widevine-dev Android branch and oemcrypto-v18 cdm branch in
sync. The commit ID for 18.4 on oemcrypto-v18 is
a2f23a2281e5e06dc2867585bdc516fa132b6396.

Merged from go/wvgerrit/190151

Bug: 290252845
Test: WVTS tests are running and passing
Change-Id: I457332e7ca70a5b5169345e1279b3eb9f18413b6

libwvdrmengine/cdm/test/create_test_file_system.cpp

@@ -4,4 +4,8 @@
 
 #include "create_test_file_system.h"
 
-wvutil::FileSystem* CreateTestFileSystem() { return new wvutil::FileSystem(); }
+#include "test_host.h"
+
+wvutil::FileSystem* CreateTestFileSystem() {
+  return new wvutil::FileSystem("", &g_host->per_origin_storage());
+}