Fix for #1888: check item's original namespace, not remapped one, for inclusion/exclusion

[skriss]

Closes #1888

cc @betta1 - would be great if you could test this out! I can push an image if you need.

[betta1]

Thanks Steve, I'll checkout your branch and build the image. I'll update in a few mins.

[betta1]

Yes this 💯 fixes #1888, tested with the build from your branch and restore works as expected:

k get po -n mysql
NAME                     READY   STATUS    RESTARTS   AGE
mysql-5c5cd4b775-lrp29   1/1     Running   0          8m28s

k get deploy -n mysql
NAME    READY   UP-TO-DATE   AVAILABLE   AGE
mysql   1/1     1            1           8m55s

k get po -n nginx
NAME                        READY   STATUS    RESTARTS   AGE
my-nginx-6cc48cd8db-zx8fh   1/1     Running   0          9m23s

k get deploy -n nginx
NAME       READY   UP-TO-DATE   AVAILABLE   AGE
my-nginx   1/1     1            1           9m45s

# back up mysql, nginx namespaces
velero backup create backup-0 --include-namespaces mysql,nginx

velero get backups
NAME       STATUS      CREATED                         EXPIRES   STORAGE LOCATION   SELECTOR
backup-0   Completed   2019-09-25 12:56:40 -0700 PDT   29d       dd-bsl             <none>

# restore mysql namespace to new namespace
velero restore create mysql-restore --namespace-mappings mysql:mysql-new --from-backup backup-0 --include-namespaces mysql

# mysql deployment and pods restored into new namespace
k get po -n mysql-new
NAME                     READY   STATUS    RESTARTS   AGE
mysql-5c5cd4b775-lrp29   1/1     Running   0          34s

k get deploy -n mysql-new
NAME    READY   UP-TO-DATE   AVAILABLE   AGE
mysql   1/1     1            1           41s