Add default brightness control

This lets user set the default brightness so user doesn't cook
their phone on first boot or loss of settings file, while
still maintaining the ability to turn brightness to max if
desired.

Change-Id: Ia801fba46014335148ec573a0b0bbdf0a3ca60ae
diff --git a/Android.mk b/Android.mk
index c57e8dc..0598796 100644
--- a/Android.mk
+++ b/Android.mk
@@ -299,6 +299,9 @@
 ifneq ($(TW_MAX_BRIGHTNESS),)
 	LOCAL_CFLAGS += -DTW_MAX_BRIGHTNESS=$(TW_MAX_BRIGHTNESS)
 endif
+ifneq ($(TW_DEFAULT_BRIGHTNESS),)
+	LOCAL_CFLAGS += -DTW_DEFAULT_BRIGHTNESS=$(TW_DEFAULT_BRIGHTNESS)
+endif
 ifneq ($(TW_CUSTOM_BATTERY_PATH),)
 	LOCAL_CFLAGS += -DTW_CUSTOM_BATTERY_PATH=$(TW_CUSTOM_BATTERY_PATH)
 endif