Tweak WallpaperManager docs

suggestDesiredDimensions() needed a somewhat different usage note.

Also added some conspicuously absent @see references.

Bug: 130832612
Test: build 'offline-sdk-docs' & inspect the result
Change-Id: Ifb6490e4aa70d84d40b56a985e38f9a3932f7d4e
1 file changed