Explicitly compile core.oat with the Quick compiler.

Change-Id: Id9e301268a75f6002855c690c9324bbcbee3ed6e
diff --git a/build/Android.oat.mk b/build/Android.oat.mk
index d4fd519..8d49565 100644
--- a/build/Android.oat.mk
+++ b/build/Android.oat.mk
@@ -52,6 +52,9 @@
     core_dex2oat_dependency := $(DEX2OAT)
   endif
 
+  ifeq ($(1),default)
+    core_compile_options += --compiler-backend=Quick
+  endif
   ifeq ($(1),optimizing)
     core_compile_options += --compiler-backend=Optimizing
     core_dex2oat_dependency := $(DEX2OAT)
@@ -163,6 +166,9 @@
     core_dex2oat_dependency := $(DEX2OAT)
   endif
 
+  ifeq ($(1),default)
+    core_compile_options += --compiler-backend=Quick
+  endif
   ifeq ($(1),optimizing)
     core_compile_options += --compiler-backend=Optimizing
     core_dex2oat_dependency := $(DEX2OAT)