Remove optimization to isInContentArea that wasn't working.

This might fix the bug where tapping outside the notification panel doesn't close it.

I'm not 100% sure because I can't reproduce this on-demand, but I think it's possible for
onSizeChanged to race with the animations and we end up with a bad rectangle.  The time
I did see it happen was tapping above the title area right after canceling a notification,
so that could explain it I think.

Bug: 3339023
Change-Id: Ic3a7f4c059e7bf6f30b864a371a0912a6414edb7