Update dexpreopt flags

Lets make them more like oneplus 6 and lets preopt user build to

BoardConfig.mk

@@ -108,15 +108,16 @@ ENABLE_CPUSETS := true
 # Crypto
 TARGET_HW_DISK_ENCRYPTION := true
 
-# Dexpreopt
+# Enable dexpreopt to speed boot time
 ifeq ($(HOST_OS),linux)
-  ifneq ($(TARGET_BUILD_VARIANT),eng)
-    ifeq ($(WITH_DEXPREOPT),)
       WITH_DEXPREOPT := true
-    endif
-  endif
+      WITH_DEXPREOPT_DEBUG_INFO := false
+      USE_DEX2OAT_DEBUG := false
+      DONT_DEXPREOPT_PREBUILTS := true
+      WITH_DEXPREOPT_PIC := true
+      WITH_DEXPREOPT_BOOT_IMG_AND_SYSTEM_SERVER_ONLY := true
+      PRODUCT_DEXPREOPT_SPEED_APPS += SystemUI
 endif
-WITH_DEXPREOPT_BOOT_IMG_AND_SYSTEM_SERVER_ONLY ?= true
 
 # Display
 MAX_VIRTUAL_DISPLAY_DIMENSION := 4096