Move AOD settings to Display page, add wallpaper option

When the ambientAod() flag is enabled, the existing AOD setting
should move from the Lock screen settings page to the Display
page.

The new setting has a dedicated subpage with a toggle on the primary
page. The subpage optionally supports toggling the ambient wallpaper
setting for supported devices only.

NO_IFTTT=These changes are new and do not require backport

Bug: 396630828
Test: manual - check display settings on device
Flag: com.android.systemui.shared.ambient_aod
Change-Id: I653e658a875b73f6af5c0aac2c5a516b674489d3