VirtualCamera: update mTokenToCameraName when unregisterCamera

When unregistering a camera, the corresponding device is removed
from mCameras but forgets to update mTokenToCameraName

Change-Id: I6521413e45350b85bcb4e32bf81fe329f1be8319
diff --git a/services/camera/virtualcamera/VirtualCameraService.cc b/services/camera/virtualcamera/VirtualCameraService.cc
index 370a5a8..7907cdb 100644
--- a/services/camera/virtualcamera/VirtualCameraService.cc
+++ b/services/camera/virtualcamera/VirtualCameraService.cc
@@ -158,6 +158,7 @@
 
   mVirtualCameraProvider->removeCamera(it->second);
 
+  mTokenToCameraName.erase(it);
   return ndk::ScopedAStatus::ok();
 }