Check SurfaceControl state while holding the WM lock

- If removeTrustedTaskOverlay() is somehow called twice with the same
  overlay, then it may pass the initial SC check before falling into
  removing the same overlay from the host

Fixes: 296744713
Test: Verify with game dashboard overlay

Change-Id: I1fdd405c692e9e1d1f2bbee1a687c9ef15ef45e8