Move SystemUI to /system_ext

we plan to forbid hidden API in product partition.
So this app should be moved to /system_ext because it uses hidden API.
It is not permanent, so they can be moved back to /product due to
needs if there isn't hidden usage anymore.

Bug: 137908189
Test: m
Test: check whether device boots successfully
Test: atest SystemUITests
Change-Id: I54f86496d4a0045af3576091cce00e5cd285b4f8
diff --git a/data/etc/CleanSpec.mk b/data/etc/CleanSpec.mk
index b76eb15..783a7ed 100644
--- a/data/etc/CleanSpec.mk
+++ b/data/etc/CleanSpec.mk
@@ -53,6 +53,8 @@
 $(call add-clean-step, rm -rf $(PRODUCT_OUT)/product/etc/permissions/com.android.settings.xml)
 $(call add-clean-step, rm -rf $(PRODUCT_OUT)/system/product/etc/permissions/com.android.launcher3.xml)
 $(call add-clean-step, rm -rf $(PRODUCT_OUT)/product/etc/permissions/com.android.launcher3.xml)
+$(call add-clean-step, rm -rf $(PRODUCT_OUT)/system/product/etc/permissions/com.android.systemui.xml)
+$(call add-clean-step, rm -rf $(PRODUCT_OUT)/product/etc/permissions/com.android.systemui.xml)
 # ******************************************************************
 # NEWER CLEAN STEPS MUST BE AT THE END OF THE LIST ABOVE THIS BANNER
 # ******************************************************************