Build without OpenCore by default, remove obsolete opt-in to stagefright.

Change-Id: I6e08d2136147f4e279f8a5b2b3837e4317faf27c
related-to-bug: 2941153
diff --git a/core/main.mk b/core/main.mk
index 3cab933..06a1fdf 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -277,6 +277,8 @@
 else # !sdk
 endif
 
+BUILD_WITHOUT_PV := true
+
 ## precise GC ##
 
 ifneq ($(filter dalvik.gc.type-precise,$(PRODUCT_TAGS)),)