@Override
    public void setGattCallbacks(@NonNull final BleManagerCallbacks callbacks) {
        super.setGattCallbacks(callbacks);
        //noinspection unchecked
        mCallbacks = (E) callbacks;
    }
When migrating from BLE Manager 2.1.1 to 2.2.0, the BleManager is no longer a template class.
Callbacks need to be passed in other way, e.g. using LiveData, RxJava or with a callback,
but the BleManager will not hold the callbacks reference.
<p>
To make the migration easier, this class behaves the same way as the old BleManager.
Replace the base class of your manager to LegacyBleManager.
@param <E> the callbacks interface.
ble/src/main/java/no/nordicsemi/android/ble/LegacyBleManager.java