theme: move TW_THEME_VERSION to variables.h

Automatically add the current theme version to the
splash and ui xmls during the build

Change-Id: I52f8cb41fabe34a8849ecc54ece3c0fb645dcd74

Android.mk

@@ -560,6 +560,12 @@ endif
 
 LOCAL_REQUIRED_MODULES += $(TWRP_REQUIRED_MODULES)
 
+TW_THEME_VERSION := $(shell echo "`grep TW_THEME_VERSION bootable/recovery/variables.h | cut -d ' ' -f 3`")
+
+LOCAL_POST_INSTALL_CMD += \
+    sed -i "s/{themeversion}/$(TW_THEME_VERSION)/" $(TARGET_RECOVERY_ROOT_OUT)/twres/splash.xml; \
+    sed -i "s/{themeversion}/$(TW_THEME_VERSION)/" $(TARGET_RECOVERY_ROOT_OUT)/twres/ui.xml;
+
 include $(BUILD_EXECUTABLE)
 
 # Symlink for file_contexts