WM callback to add/remove display in topology[2/2]

For External Display use Allowed semantics instead
of Enabled

Change-Id: I9636f31bff0cf3ace9e38f37d3460fddfe25fa3d
Bug: 384013689
Flag: com.android.server.display.feature.flags.display_topology
Test: DisplayManagerServiceTest, DisplayTopologyCoordinatorTest