Add errorprone for static code analysis

[MinnDevelopment]

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Changes

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Closes Issue: NaN

Description

This will ensure we properly apply @Override on methods that should have it.

[arif-banai]

this PR would resolve a bug I've encountered when run with Turkish Locale.

When a user from Turkey ran my bot, I noticed this in the debug logs:
[DEBUG] [AudioWebSocket]: Using encryption mode aead_aes256_gcm_rtpsıze

This causes the audio connection to fail:

[DEBUG] [AudioWebSocket]: The Audio connection was closed!
[DEBUG] [AudioWebSocket]: Reason: Unknown encryption mode.

I was able to resolve this error by having the user run my bot with the following java args:
-Duser.language=en -Duser.country=US

The change made in AudioEncryption.java to use Locale.ROOT should fix this bug.

JDA/src/main/java/net/dv8tion/jda/internal/audio/AudioEncryption.java

Line 34 in c82623d

this.key = name().toLowerCase(Locale.ROOT);