Remove userSerial param from vold methods that don't use it

The userSerial parameter is being removed from the vold methods that
don't use it.  Update the callers accordingly.

Note: later CLs will remove the serialNumber parameter from methods in
StorageManagerService too.  This CL simply updates the calls to vold.

Bug: 316035110
Test: presubmit
Flag: N/A, mechanical refactoring
Change-Id: Ide5397693d594e0b1fad81c031e3c9190fd0bdde