feat(fluent-bit): support various overrides on fluent-bit service.yaml

[DandyDeveloper]

Istio by default is interpreting the protocol via protocol selection. https://istio.io/latest/docs/ops/configuration/traffic-management/protocol-selection/#explicit-protocol-selection

Current configuration breaks as the Istio sidecar doesn't seem to be able to pass HTTP content over to the HTTP Metrics API with the default service configuration:

    [SERVICE]
        Daemon Off
        Flush 1
        Log_Level info
        Parsers_File /fluent-bit/etc/parsers.conf
        Parsers_File /fluent-bit/etc/conf/custom_parsers.conf
        HTTP_Server On
        HTTP_Listen 0.0.0.0
        HTTP_Port 2020
        Health_Check On

If we change the name: prefix to tcp instead, Istio seems happier with this and doesn't give the typical 503 error.

This change just gives basic support for changing attributes in the service.yaml that users might need access to.

[DandyDeveloper]

@stevehipwell @edsiper Can I get some eyes on this?