Fix certificate issue with use buildset registry

Use buildset_registry_alias for certificate file name to address
'unknown certificate authority' issue on consumer side when using standalone
use-buildset-registry role.

Issue is not visible with opendev parent jobs because certificate is handled
in pull-from-intermediate-registry role there.

Change-Id: Ieaf43be0dd4ccb92a8240a493ee6636a23c9d484
Signed-off-by: Andrii Ostapenko <andrii.ostapenko@att.com>

roles/use-buildset-registry/tasks/main.yaml

@@ -38,7 +38,7 @@
   become: true
   copy:
     content: "{{ buildset_registry.cert }}"
-    dest: "{{ ca_dir }}/buildset-registry.crt"
+    dest: "{{ ca_dir }}/{{ buildset_registry_alias }}.crt"
   register: _tls_ca
 - name: Update CA certs
   command: "{{ ca_command }}"