Use our ubuntu openafs ppa on debian

Stable Debain hasn't updated its openafs packages yet to fix the bit
masking problem. This breaks our testing for zuul jobs. Try the bionic
package from our ppa on debian instead.

Change-Id: I2ab469c984ae7d90d2a87abb2e4b29250c9bc8c2

roles/openafs-client/tasks/openafs-client/Debian.yaml

@@ -3,7 +3,7 @@
 # everywhere but our legacy Xenial x86 hosts (Debian stable has 1.8
 # inbuilt so we are good there).
 # https://bugs.launchpad.net/ubuntu/+source/openafs/+bug/1832690
-- name: Install openstackci openafs PPA
+- name: Install openstackci openafs PPA on Ubuntu
   apt_repository:
     repo: 'ppa:openstack-ci-core/openafs'
   when:
@@ -12,6 +12,16 @@
         ansible_architecture == 'x86_64' )
   become: yes
 
+# We install the ppa on debian too in order to get the fixed pacakages
+# in our PPA
+- name: Install openstackci openafs PPA on Debian
+  apt_repository:
+    repo: 'ppa:openstack-ci-core/openafs'
+    codename: bionic
+  when:
+    - ansible_distribution == 'Debian'
+  become: yes
+
 - name: Install kernel headers dependency
   package:
     name: