Fixed exceptions during test tearDown

- Acquire WM lock when tearing down test. Prevent the handler thread
from modifying state at the same time.
- Don't set surface boundaries on window states without a surface
control.
- Avoid exception if process can read screen-edge-insets for Pip.

Change-Id: If4a2438032866eaec84ed79c30c1d716e0f89758
Fixes: 38113905
Test: this is it!