Fixed a measuring bug with the notification children container

The notification children didn't respect the given dimensions
when measuring and was simply measuring itself as high as desired.
This lead to a bug where the parent could crash when a layer was
set on it.
We are now measuring the container at most with the height of
the given size and let children draw over our view bounds.
In oder to still allow touch in those regions we also
override the touch rect.
This also simplifies the rest of the touch handling.

Bug: 26159274
Change-Id: I728553a6386455e6632e2511be8a3e7cb447e89b