PL2: Set default brightness at 30

BoardConfig.mk

@@ -87,6 +87,7 @@ AB_OTA_UPDATER := true
 TW_THEME := portrait_hdpi
 TW_INCLUDE_CRYPTO := true
 TW_MAX_BRIGHTNESS := 100
+TW_DEFAULT_BRIGHTNESS := "30"
 TW_BRIGHTNESS_PATH := "/sys/class/leds/lcd-backlight/brightness"
 TW_EXCLUDE_SUPERSU := true
 TW_EXTRA_LANGUAGES := true