Add permissions for default AOSP wallpaper picker app

We need CUSTOMIZE_SYSTEM_UI to query for SysUI Flags to determine the
app's capabilities, and to get the tests to work properly.

Bug: 267185017
Test: atest WallpaperPicker2Tests
Change-Id: Icd446ec0125cfd9687271ca0e8cfaa325a79ae6f
1 file changed