Enable Multiline mode On in Fluent Bit Helm

I'm seeing the `dockerMode` is set to `On ` by default and not overridable. Also, template does not have a way to enable `Multiline`. Is this by the design?

https://github.com/aws/eks-charts/blob/e351927cb4c19c02cd2b8c0642c1953ec39ae1ff/stable/aws-for-fluent-bit/values.yaml#L27

I have some multiline logs which are not in JSON format which I want to combine, how can I achieve this?

My logs looks like
```
2020-11-11 11:45:17.323 WARN 1 --- [nio-8080-exec-1] .m.m.a.ExceptionHandlerExceptionResolver : Resolved [org.springframework.orm.ObjectOptimisticLockingFailureException: Object of class .....
```