core: always update volume size when creating a new image

Vdsm often aligns the size of the volume when creating, and the volume
will end up having a different size in the engine than what is on the
storage. This is already handled when a new disk is created but not when
a new snapshot is created.

Since there is already a getVolumeInfo request at the end of snapshot
creation, we can use this opportunity to update the size of the volume
as well.

Bug-Url: https://bugzilla.redhat.com/1852308
Signed-off-by: Benny Zlotnik <bzlotnik@redhat.com>

backend/manager/modules/bll/src/main/java/org/ovirt/engine/core/bll/storage/disk/image/BaseImagesCommand.java

@@ -384,6 +384,9 @@ protected void endSuccessfully() {
                                 newStorageDomainID,
                                 getDestinationDiskImage());
                     }
+
+                    // Update disk's size if it's changed
+                    getDestinationDiskImage().setSize(newImageIRS.getSize());
                 }
             } catch (EngineException e) {
                 // Logging only