Give IMEs the entire screen to use for measuring purposes.

IMEs recently gained the ability to layout out under the nav bar,
but our core measuring logic does not give height=WRAP_CONTENT windows
the entire screen height when computing desired window height.

Since IMEs can be identified by type, let them use the entire screen
height for measuring purposes, to properly handle the cases where
space is constrained, making that unaccounted-for nav bar height
important.

Bug:11215678
Change-Id: I1d0b73454c0c629e7d669b9de70641c7e8c4d333