Add a new API to display volumes summary with total number of volumes
and total size in GB (total_size: 500 and total_count: 20).
DocImpact
APIImpact
Partially-Implements: blueprint display-volumes-summary-details
Co-Authored-By: MR Swami Reddy <swamireddy@gmail.com>
Change-Id: I0117a233afbd834a165ade9e1358f8dd38fbcfac