Improve `0.7.x` Helm Compatibility.

[MarcusSorealheis]

Two weeks ago, we released: v0.7.0. Since then, we have received many comments about a 0.7.0 Helm release. We need to modify Nativelink to support Helm deployments. In v0.7.0 we dropped support for experimental and highly customized Prometheus deployment in favor of a standards-driven Open Telemetry implementation. The Open Telemetry isn't entirely integrated/merged, which is part of what we need to address.

[amankrx]

I guess we can utilize the changes we have made so far to update the Helm chart here. I will create a draft PR to introduce these changes

[MarcusSorealheis]

@amankrx is this ready?