Regenerate the grid when dragging a tile out of bounds

This removes any leftover spacers once a tile is removed during a drag movement

Test: manually dragging tiles out of the grid
Flag: com.android.systemui.qs_ui_refactor_compose_fragment
Fixes: 379311650
Change-Id: I2e20d4bfda56a234dfc39da6a0a98c0f72ec8f34