Tweak TopologyScale API according to current usage

Use Float rather than Int for View coordinates as mostly Floats are
required. Also stop requiring Point/PointF boxing of arguments, since
the Preference implementation ended up not using Point/PointF objects
very much.

Flag: com.android.settings.flags.display_topology_pane_in_display_list
Bug: b/352650922
Test: atest DisplayTopologyPreferenceTest.kt
Change-Id: Iecccb9d524014c3b6ad600f99b9e769418e57a4d