omni: remove stock theme overlay

and move pixel to vendor/overlay where it belong

Change-Id: I19bde5b301d821b1e3b8632a00590f0824bab649
diff --git a/google/themes/Pixel/Android.mk b/google/themes/Pixel/Android.mk
index 7c260ae..37bd941 100644
--- a/google/themes/Pixel/Android.mk
+++ b/google/themes/Pixel/Android.mk
@@ -1,11 +1,11 @@
 LOCAL_PATH:= $(call my-dir)
 include $(CLEAR_VARS)
 
-LOCAL_MODULE_TAGS := optional
-
 LOCAL_PACKAGE_NAME := PixelTheme
-LOCAL_SDK_VERSION := current
+LOCAL_RRO_THEME := PixelTheme
 LOCAL_CERTIFICATE := platform
-LOCAL_PRIVILEGED_MODULE := false
+LOCAL_MODULE_TAGS := optional
+LOCAL_SRC_FILES := $(call all-subdir-java-files)
+LOCAL_RESOURCE_DIR := $(LOCAL_PATH)/res
 
-include $(BUILD_PACKAGE)
+include $(BUILD_RRO_PACKAGE)