Close the load screen faster on pre-quota devices.

Pre-quota devices can take an absurd time to load. By loading the screen
once the volume sizes load, we can just show "calculating..." for a
really long time instead of a loading screen.

Change-Id: Id8ab0609c2bc19531d530c6bdf6bff89c5bfac96
Fixes: 64150148
Test: Settings Robotest