Enable WITH_DEXPREOPT on devices where it is possible

Change-Id: I0ea9768f801865f95f2774b8377cc8f3d75e30bf
(cherry picked from commit 35251f09)

BoardConfigCommon.mk

@@ -68,6 +68,14 @@ TARGET_USES_OVERLAY := true
 TARGET_USES_SF_BYPASS := true
 TARGET_USES_C2D_COMPOSITON := true
 
+# Enable dex-preoptimization to speed up first boot sequence
+ifeq ($(HOST_OS),linux)
+  ifeq ($(TARGET_BUILD_VARIANT),user)
+    ifeq ($(WITH_DEXPREOPT),)
+      WITH_DEXPREOPT := true
+    endif
+  endif
+endif
 WITH_DEXPREOPT_BOOT_IMG_ONLY ?= true
 
 TARGET_USERIMAGES_USE_EXT4 := true