Fix flashing dialogs when IME enters/exits.

The flashing is caused by changing the shown frame of the window
prematurely, before the animation kicks in. After the animation kicks
in, the shown frame goes back to the original position and then animates
to the final position.

We need the shown calculation to happen during layout for resizing and
the layout might be triggered at any time before the animation is run.
In order to avoid flashing, we don't calculate shown frame for windows
that are animating during the layout and let the animation position the
shown frame correctly later.

Includes also logging for inset setting, which triggers layout run.

Bug: 26323134
Change-Id: Ibe1efae798415d3564c659aa94c2b94af92c743a