[RHOCP4.11] Logs of POD which doesn't have labels specified by structuredTypeKey are parsed to JSON, and forwarded to app-xxxxxx

Description of problem:

Logs of POD which doesn't have labels specified by structuredTypeKey are parsed to JSON, and forwarded to app-xxxxxx.
This will cause type conflicts and cardinality problem described at docs [1].

[1] https://access.redhat.com/documentation/en-us/openshift_container_platform/4.11/html-single/logging/index#cluster-logging-configuration-of-json-log-data-for-default-elasticsearch_cluster-logging-enabling-json-logging

Version-Release number of selected component (if applicable):

OpenShift v4.11.5 with OpenShift Logging 5.5.3.

How reproducible:

Always

Steps to Reproduce:

Step1. Deploy app which emits JSON log messages.Step2. Create the following CLF CR and aplly it.

apiVersion: "logging.openshift.io/v1"
kind: ClusterLogForwarder
metadata:
  name: instance
  namespace: openshift-logging
spec:
  inputs:
  - name: structuredTypeKey-k8slabels
    application:
      namespaces:
        - my-app
  outputDefaults:
    elasticsearch:
      structuredTypeKey: kubernetes.labels.k8slabels
  pipelines:
  - name: structuredTypeKey-k8slabels
    inputRefs:
    - structuredTypeKey-k8slabels
    outputRefs:
    - default
    parse: json

Step3. Check forwarded logs.

Actual results:

Logs from app are parsed to JSON, and forwarded to app-xxxxxx.

Expected results:

Logs from app are not parsed to JSON.