DO NOT MERGE Don't restore focus on new HUN window

When a HUN window shows for the first time, Android framework can try to
find a default focus. As such, the FPV may try to focus the topmost HUN
by default, without having nudged to the HUN window.

Bug: 175897692
Test: manual (reboot and trigger HUN via kitchen sink)
Change-Id: I7e1707cab8200c6a17b89416ac091fae6aeb2226
1 file changed