disposeCamera method
override
    Closes and releases the camera.
This is separate from dispose so the isolate can keep reporting its status.
Implementation
@override
void disposeCamera() {
  camera.stopStream();
  camera.dispose();
}
Closes and releases the camera.
This is separate from dispose so the isolate can keep reporting its status.
@override
void disposeCamera() {
  camera.stopStream();
  camera.dispose();
}