Update the number of columns on config change in share sheet

mMaxTargetsPerRow wasn't updated in the chooser
multi profile pager adapter, this adapter sets
the number of columns in the grid layout manager.
This led to incorrect number of columns when display
size changes in runtime.

Bug: 235572712
Test: open share sheet, fold the device =>
 check that the number of columns is updated
Change-Id: I1f3f3bff8a4d23909ccd4c00b74091183c28821b