Fix inadvertent submission in last CL.

Change-Id: I3f8c55832dbee39b0cb8d1a245a72eef6f7b911c
diff --git a/build/Android.common.mk b/build/Android.common.mk
index dd8a483..8c16295 100644
--- a/build/Android.common.mk
+++ b/build/Android.common.mk
@@ -60,7 +60,7 @@
 	dalvik/libdex
 
 art_cflags := \
-	-O0 \
+	-O2 \
 	-ggdb3 \
 	-Wall \
 	-Werror \