Automatic merge from submit-queue (batch tested with PRs 39625, 39842)
AWS: Remove duplicate calls to DescribeInstance during volume operations
This change removes all duplicate calls to describeInstance
from aws volume code path.
**What this PR does / why we need it**:
This PR removes the duplicate calls present in disk check code paths in AWS. I can confirm that `getAWSInstance` actually returns all instance information already and hence there is no need of making separate `describeInstance` call.
Related to - https://github.com/kubernetes/kubernetes/issues/39526
cc @justinsb @jsafrane
e1fa1512e4