Fix for sidecar installation failure if k8s worker nodes are not in ~/.ssh/known_hosts

[sharmilarama]

Description

This PR addresses an issue with sidecar installation failure when the remote k8s worker nodes have not yet been added to the ~/.ssh/known_hosts file. While running SSH commands to check connectivity to the authorization proxy there is an additional message in the response "Warning: Permanently added '1.2.3.4' (ECDSA) to the list of known hosts.". This PR adds changes to ignore this warning message to get the response code in the next line.

GitHub Issues

GitHub Issue #
dell/csm#147

Checklist:

• I have performed a self-review of my own code to ensure there are no formatting, vetting, linting, or security issues
• I have verified that new and existing unit tests pass locally with my changes
• I have not allowed coverage numbers to degenerate
• I have maintained at least 90% code coverage
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• Backward compatibility is not broken

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Please also list any relevant details for your test configuration

• Tested verify,sh script for driver installation.