Add new callback for when activity rotates

Launcher needs to distinguish display changes
that result naturally vs apps that launch
in a fixed portrait/landscape rotation during
the quickstep gesture.This callback helps anticipate
if a subseqent onDisplayChanged() will
have resulted from a natural rotation or not.

Bug: 154580671
Change-Id: I59ee7985a9f367e8fc5826c08476c1a25d1426b0