No way to specify TLS disabled for Kafka scaler

[gunniwho]

Report

When using the Apache Kafka scaler, you can set the auth parameter tls to enabled for the underlying kafka client to use tls when connecting to the brokers. There is no way however to set tls to anything else to configure tls to be disabled. See here. Now I know that the default behavior is that tls is off but the current behavior is counter-intuitive.

Expected Behavior

tls: disabled is not invalid and means the same as not specifying the parameter

Actual Behavior

The scaler throws an error

Steps to Reproduce the Problem

1. Create a trigger authentication resource that exposes the tls parameter as "disabled"
2. Create a kafka scaler that references the trigger auth
3. The scaler can't be created because the tls value is invalid

Logs from KEDA operator

No response

KEDA Version

2.6.0

Kubernetes Version

1.20

Platform

Amazon Web Services

Scaler Details

Kafka

Anything else?

No response

[tomkerkhove]

Thank you for the PR!