Disable obsolete eng Makefile rule

Change-Id: I729dd4b4387b069ca1fa234e58f7207d757e9c03
diff --git a/Chromium/Android.mk b/Chromium/Android.mk
index 3e56624..067cc2f 100644
--- a/Chromium/Android.mk
+++ b/Chromium/Android.mk
@@ -19,7 +19,7 @@
 
 include $(CLEAR_VARS)
 LOCAL_MODULE := Chromium
-LOCAL_MODULE_TAGS := eng optional
+LOCAL_MODULE_TAGS := optional
 LOCAL_MODULE_CLASS := APPS
 ifeq ($(TARGET_ARCH), x86)
 LOCAL_SRC_FILES := Chromium_x86.apk