libmedia: fix all warning, make warnings errors, use clang

Change-Id: Ic00d2c5d0bbb1605e96666e25c9ccc22bea6d3ff
diff --git a/media/libmedia/MediaResourcePolicy.cpp b/media/libmedia/MediaResourcePolicy.cpp
index 2bb996a..139a38c 100644
--- a/media/libmedia/MediaResourcePolicy.cpp
+++ b/media/libmedia/MediaResourcePolicy.cpp
@@ -42,7 +42,7 @@
 
 String8 MediaResourcePolicy::toString() const {
     String8 str;
-    str.appendFormat("%s:%llu", mType.string(), mValue);
+    str.appendFormat("%s:%llu", mType.string(), (unsigned long long)mValue);
     return str;
 }