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

Change-Id: Ic00d2c5d0bbb1605e96666e25c9ccc22bea6d3ff
diff --git a/media/libmedia/MemoryLeakTrackUtil.cpp b/media/libmedia/MemoryLeakTrackUtil.cpp
index d31f721..554dbae 100644
--- a/media/libmedia/MemoryLeakTrackUtil.cpp
+++ b/media/libmedia/MemoryLeakTrackUtil.cpp
@@ -173,7 +173,7 @@
 
 #else
 // Does nothing
-void dumpMemoryAddresses(int fd) {}
+void dumpMemoryAddresses(int fd __unused) {}
 
 #endif
 }  // namespace android