START battle effect doesn't work

## Description
The `START` battle action in pixelevents doesn't trigger

## How to reproduce
Steps to reproduce the behavior:
1. Create and install a resource pack that uses the START battle action event
2. Enter battle
3. See lack of music

## Context
Pixelmon Version: 9.1.6
PixelTweaks Version: 1.8.3
Server or Single Player: Single
