AOSP/WallpaperPicker - update the WallpaperPicker test package version to target P (28) or higher. am: f147ac2fdb am: b50b0d2d71 am: 7e4e26fee6 am: 4fd92c6175

Change-Id: I6b536269dd2bb3f6d24a23c9650a2a1ebe0e6212