Remove the redundant DISABLE_DEXPREOPT

To disable dexpreopt, use just:
WITH_DEXPREOPT=false

Change-Id: I5804f3774f8ec50eb16c5336776dbce0c28b16d9

core/dex_preopt.mk

@@ -71,5 +71,4 @@ endif
 else
 $(warning No DALVIK_VM_LIB, disable dexpreopt.)
 WITH_DEXPREOPT := false
-DISABLE_DEXPREOPT := true
 endif  # DALVIK_VM_LIB is defined.

core/main.mk

@@ -343,7 +343,7 @@ ifneq (,$(user_variant))
   # Turn on Dalvik preoptimization for user builds, but only if not
   # explicitly disabled and the build is running on Linux (since host
   # Dalvik isn't built for non-Linux hosts).
-  ifneq (true,$(DISABLE_DEXPREOPT))
+  ifeq (,$(WITH_DEXPREOPT))
     ifeq ($(user_variant),user)
       ifeq ($(HOST_OS),linux)
         WITH_DEXPREOPT := true

target/board/generic_x86/BoardConfig.mk

@@ -24,7 +24,7 @@ BOARD_MALLOC_ALIGNMENT := 16
 # Enable dex-preoptimization to speed up the first boot sequence
 # of an SDK AVD. Note that this operation only works on Linux for now
 ifeq ($(HOST_OS),linux)
-WITH_DEXPREOPT := true
+WITH_DEXPREOPT ?= true
 endif
 
 # Build OpenGLES emulation host and guest libraries

target/board/generic_x86_64/BoardConfig.mk

@@ -30,7 +30,7 @@ BOARD_MALLOC_ALIGNMENT := 16
 # Enable dex-preoptimization to speed up the first boot sequence
 # of an SDK AVD. Note that this operation only works on Linux for now
 ifeq ($(HOST_OS),linux)
-WITH_DEXPREOPT := true
+WITH_DEXPREOPT ?= true
 endif
 
 # disable the emulator

target/board/vbox_x86/BoardConfig.mk

@@ -3,7 +3,6 @@
 #
 
 TARGET_ARCH=x86
-DISABLE_DEXPREOPT := true
 TARGET_COMPRESS_MODULE_SYMBOLS := false
 TARGET_NO_RECOVERY := true
 TARGET_HARDWARE_3D := false
@@ -32,6 +31,7 @@ TARGET_USERIMAGES_SPARSE_EXT_DISABLED := true
 # Reserve 265M  for the system partition
 BOARD_SYSTEMIMAGE_PARTITION_SIZE := 268435456
 
+WITH_DEXPREOPT := false
 
 # The eth0 device should be started with dhcp on boot.
 # Useful for emulators that don't provide a wifi connection.