Description
It has found that error is triggered during update cluster functionality on selecting Schedule a different time

Steps to reproduce:
 # Launch OCM UI.
 # Open an OSD cluster and schedule an click on upgrade.
 # Update cluster modal is open.
 # Chose whatever the version and click on Next
 # Click on "Schedule a different time"
 # "this.getDefaultTimestamp is not a function" Error is thrown

Actual results:

Error is thrown

Expected results:

Date and time selection should be shown