Always update PageIndicator visibility

Even if the number of childCount of the PageIndicator matches the new
number of pages being set, update the PageIndicator's visibility in case
this is the first time PageIndicator is being set to visible.

Test: Reboot device, fully expand QS with more
than one page of tiles -> should be able to see
the PageIndicator
Fixes: 158118587

Change-Id: I20cc995cfe6d92b730ce722c924b945bfa1c6bde