Roughly fix layout of PageActionIconView in CR2023

This broke when we changed icon sizes and inkdrop shapes around them to
be circular. These insets didn't work well for the label-showing case.

The insets ballparked aren't final as these items haven't been spec'd
but minor updates should be easier to do on top of this.

To support this we let the IconLabelBubbleView UpdateBorder be called
when animations end (so the expanded-state background can use different
insets). We let PageActionIconView override UpdateBorder instead of
rolling its own UpdatePageActionIconBorder method.

We also merge IconLabelBubbleView::GetInternalSpacing() back from
LocationIconView as the internal spacing looks reasonable for both cases
tried.

Bug: 1447066
Change-Id: If84ca5233c427e1a50dcc23531e6ba8e2b675092
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4549772


Reviewed-by: Shibalik Mohapatra <shibalik@chromium.org>
Code-Coverage: Findit <findit-for-me@appspot.gserviceaccount.com>
Commit-Queue: Peter Boström <pbos@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1147548}