Fix volume not expanded when using authorization's volumePrefix

[AkshaySainiDell]

Description

Update code to account for the volmuePrefix added by the authorization module.

GitHub Issues

List the GitHub issues impacted by this PR:

GitHub Issue #
dell/csm#1663

Checklist:

• Have you run format,vet & lint checks against your submission?
• Have you made sure that the code compiles?
• Did you run the unit & integration tests successfully?
• Have you maintained at least 90% code coverage?
• Have you commented your code, particularly in hard-to-understand areas
• Have you done corresponding changes to the documentation
• Did you run tests in a real Kubernetes cluster?
• 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

• Installed driver with authorization and ran volume expansion test
  

• Installed driver on a kubernetes cluster and ran volume expansion test