RootViewImpl: Fix measure size hint for WRAP_CONTENT windows

Fixes an issue where we would measure WRAP_CONTENT windows inconsistently
in the measure passes before and after relayoutWindow.

Fixes: 119839070
Bug: 73813813
Change-Id: I376e416d648f31a0dedecd6a70b476c3bf82b8b0
Test: Install test case app from 119839070, verify dialog is correctly laid out.