Update aconfig flag for persisting display size in connected displays

This flag was incorrectly marked as Bug-fix, flag name is updated with this change to create a new workflow.

Flag: com.android.window.flags.enable_persisting_display_size_for_connected_displays
RenamedFlag: com.android.window.flags.enable_persisting_density_scale_for_connected_displays
Test: NA
Bug: 392855657
Change-Id: I9d383f19d6398eeb5c47699768c3ff5b3cd388fd