injectBleDeviceManagerForTest method
Injects a Capture instance as the BLE device manager.
This seam is required for unit tests that need to verify _getBle/_setBle calls without triggering a real deviceManagerArrival event cycle.
Implementation
// ignore: use_setters_to_change_properties
void injectBleDeviceManagerForTest(Capture bleDeviceManager) {
_bleDeviceManager = bleDeviceManager;
}