Created systemui/new_picker_ui flag (1/2)

This flag is going to be used in SysUI and Launcher. Thus removed the one in customization_picker and create the new one in systemui.

Test: Build success
Bug: 339081035
Flag: com.android.systemui.new_picker_ui
Change-Id: I908b325f58f6e6ce5312845d55bc4a5f4ef97928