Change the image tag to tip in the Helm values (defaults)

[Xin Hao]

Just like what https://github.com/apache/flink-kubernetes-operator/blob/main/helm/flink-kubernetes-operator/values.yaml#L28 does.

Can we change the default image tag in the Helm values to tip?
If the end users want to specify the version, they should override the field and defaults to tip (latest) for others.

cc @jacksonrnewhouse

[Edmondo Porcu]

@haoxins will take care of this after we merge #271

[Xin Hao]

thanks

[Edmondo Porcu]

I think it's good to leave it open until PR are merged