gerrit: fix Launchpad credentials write

The extant variable name is never set so this never writes anything
out.  Move it to a dictionary value.  Use stub values for testing,
this way we don't need the "when:".

Additionally remove an unused old template file.

Change-Id: Id96fde79e28f309aa13e16bdda29f004c3c69c4b

modules/openstack_project/templates/infra_lp_creds.erb

@@ -1,5 +0,0 @@
-[1]
-access_token = <%= @lp_access_token %>
-access_secret = <%= @lp_access_secret %>
-consumer_key = <%= @lp_consumer_key %>
-consumer_secret =

playbooks/roles/gerrit/tasks/main.yaml

@@ -185,6 +185,8 @@
     group: "{{ gerrit_user_name }}"
     mode: 0775
 
+# The hook scripts below use update-bug (provided by jeepyb) and this
+# authentication file.
 - name: Write Launchpad creds file
   template:
     src: infra_lp_creds.j2
@@ -192,7 +194,6 @@
     owner: "{{ gerrit_user_name }}"
     group: "{{ gerrit_user_name }}"
     mode: 0600
-  when: lp_access_token is defined
 
 - name: Copy static hooks
   copy:

playbooks/roles/gerrit/templates/infra_lp_creds.j2

@@ -1,5 +1,5 @@
 [1]
-access_token = {{ gerrit_lp_access_token }}
+access_token = {{ gerrit_launchpad_auth['access_token'] }}
-access_secret = {{ gerrit_lp_access_secret }}
+access_secret = {{ gerrit_launchpad_auth['access_secret'] }}
-consumer_key = {{ gerrit_lp_consumer_key }}
+consumer_key = {{ gerrit_launchpad_auth['consumer_key'] }}
 consumer_secret =

playbooks/zuul/templates/group_vars/review.yaml.j2

@@ -100,3 +100,7 @@ gerrit_email_private_key: wjpkxebohgbid6rpuwpfrYsouxpgseluqir6yupppBczoezj
 gerrit_rest_token_private_key: A83fAC8x72wxcu
 gerrit_container_image: "docker.io/opendevorg/gerrit:{{ zuul_test_gerrit_version | default('3.2') }}"
 gerrit_under_test: true
+gerrit_launchpad_auth:
+  access_token: 'token'
+  access_secret: 'secret'
+  consumer_key: 'consumer_key'