Rename metrics.proto to wv_metrics.proto.

Merge from http://go/wvgerrit/105767

To avoid conflict with metrics.proto in
frameworks/av/drm/libmediadrm/proto.
This is in preparation of moving metrics_dump tool
to build under Android.

bug: 161783052
Test: unit test
Test: Play Movies & Tv and Netflix streaming
Change-Id: I2406b66db4d61cca7c6260ea8847a555d96c8d42

libwvdrmengine/cdm/test/wv_cdm_metrics_test.cpp

@@ -8,12 +8,12 @@
 #include "cdm_identifier.h"
 #include "gmock/gmock.h"
 #include "log.h"
-#include "metrics.pb.h"
 #include "string_conversions.h"
 #include "test_base.h"
 #include "test_printers.h"
 #include "wv_cdm_types.h"
 #include "wv_content_decryption_module.h"
+#include "wv_metrics.pb.h"
 
 using ::testing::Eq;
 using ::testing::Ge;