Added validation / normalized resources for storage-related operations.
Added validation / normalized resources for storage-related operations.

When the storage-related operations were added, the cases were added to
the `switch` but the corresponding validation / normalization code was
not added. This patch adds the missing code.

Review: https://reviews.apache.org/r/64737

reneploetz/mesos,abudnik/mesos,dforsyth/mesos,abudnik/mesos,reneploetz/mesos,Gilbert88/mesos,andschwa/mesos,abudnik/mesos,jpeach/mesos,kaysoky/mesos,abudnik/mesos,Gilbert88/mesos,chhsia0/mesos,gsantovena/mesos,andschwa/mesos,dforsyth/mesos,jpeach/mesos,andschwa/mesos,asamerh4/mesos,chhsia0/mesos,reneploetz/mesos,Gilbert88/mesos,asamerh4/mesos,Gilbert88/mesos,gsantovena/mesos,gsantovena/mesos,kaysoky/mesos,chhsia0/mesos,kaysoky/mesos,asamerh4/mesos,jpeach/mesos,Gilbert88/mesos,andschwa/mesos,andschwa/mesos,asamerh4/mesos,abudnik/mesos,reneploetz/mesos,reneploetz/mesos,chhsia0/mesos,reneploetz/mesos,kaysoky/mesos,kaysoky/mesos,kaysoky/mesos,abudnik/mesos,jpeach/mesos,jpeach/mesos,jpeach/mesos,gsantovena/mesos,chhsia0/mesos,Gilbert88/mesos,Gilbert88/mesos,dforsyth/mesos,reneploetz/mesos,dforsyth/mesos,chhsia0/mesos,andschwa/mesos,dforsyth/mesos,gsantovena/mesos,gsantovena/mesos,chhsia0/mesos,kaysoky/mesos,andschwa/mesos,gsantovena/mesos,abudnik/mesos,asamerh4/mesos,asamerh4/mesos,jpeach/mesos,dforsyth/mesos,asamerh4/mesos,dforsyth/mesos