Description of problem:
When we have a namespace with a PVC attached to a pod and we create a migration plan for this namespace. If the migration plan maps the namespace to another name in the target cluster, a wrong PvUsageAnalysisFailed warning is displayed in the migplan.

Version-Release number of selected component (if applicable):
MTC 1.5.0
TARGET CLUSTER: OCP 4.8 AWS (gp2)
SOURCE CLUSTER: OCP 3.11 AWS (gp2)
REPLICATION REPOSITORY: AWS S3

How reproducible:
Always

Steps to Reproduce:
1. Deploy a sample django application
 $ oc new-project bz-test
 $ oc new-app django-psql-persistent


2. Create a migration plan for this namespace and map the namespace to another name. "bz-test-mapped" for instance


Actual results:
The migration plan will become ready, but it will display a PvUsageAnalysisFailed warning 
  - category: Warn
    lastTransitionTime: "2021-05-31T14:43:45Z"
    message: 'Failed to compute PV resizing data for the following volumes. PV resizing
      will be disabled for these volumes and the migration may fail if the volumes
      are full or their requested and actual capacities differ in the source cluster.
      Please ensure that the volumes are attached to one or more running Pods for
      PV resizing to work correctly: [pvc-69a1dd43-c21c-11eb-a9dd-0eeaed03c931]'
    reason: NotDone
    status: "True"
    type: PvUsageAnalysisFailed


Expected results:
The pvc is properly attached, so this warning should not be displayed.

Additional info: