Shell script install-logging.sh used in task install-logging-operator has below issue:

Current Issue:
Task install-logging-operator sets default value of CHANNEL to 'stable-6.2', due to issue in shell script always CHANNEL is set to default value passed in task, without honoring if elif conditions in the script.
Ex: For OCP 4.15, CHANNEL should resolve to stable-6.1, but if set to default value set in task.

Fix Provided:
 CHANNEL should resolve to a value based on if else conditions set on OCP VERSION, If it does not resolve to any value due to unknown reasons (exceptions etc, default value set for CHANNEL parameter in task  install-logging-operator should be picked.
For OCP 4.20.x & above, channel will resolve to stable-6.4 & for below versions it will resolve to stable-6.3 (Since OCP 4.14 is EOF)