spec: Run pre/post-install stuff on 'daemon-driver-storage-core'

spec: Run pre/post-install stuff on 'daemon-driver-storage-core'

'daemon-driver-storage' is just a meta-package, the actual daemon is in
the 'daemon-driver-storage-core' package, so without installing the meta
package the storage daemon is not being enabled.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2025644
Fixes: 50eae3f8859, b8ef6255444
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Andrea Bolognani <abologna@redhat.com>