Fixed an issue where the heads-up icon location was wrong

Because of configuration changes, old listeners would still
be influencing the icon location, even after they were detached.

Test: runtest systemui
Test: change density, get heads-ups, observe correct position
Change-Id: I35f4c905ab8a6025476c582dcbc7e85a5eff23f5
Fixes: 76084585
5 files changed