Changing difficulty after Raid begins does not change the number Raid waves.

Steps to Reproduce:

1. Get bad omen
2. Go to a village on hard difficulty
3. Set the difficulty to easy when the raid bar shows up

Observed Results:

Raids go on too far when they are in a certain difficulty, if they are triggered in hard mode but the difficulty is changed to easy

Expected Results:

The raid should only be however many waves the difficulty is