Move jgit autogc disablement into correct config

The receive.autogc configuration apparently needs to be in its own
file, not in the general gerrit.conf. Move it to the correct
location.

https://review.opendev.org/Documentation/config-gerrit.html#jgit-receive

While we're here, correct the filename on the gerrit.config and
secure.config templates to make it clear they're jinja2 files, and
add a file mode to the replication.config where it was missing.

Change-Id: I9243bccac103c51ee435725aae482731642a37cc

playbooks/roles/gerrit/files/jgit.config

@@ -0,0 +1,2 @@
+[receive]
+	autogc = false

playbooks/roles/gerrit/tasks/main.yaml

@@ -63,7 +63,7 @@
 
 - name: Write Gerrit config file
   template:
-    src: gerrit.config
+    src: gerrit.config.j2
     dest: "{{ gerrit_site_dir }}/etc/gerrit.config"
     owner: "{{ gerrit_user_name }}"
     group: "{{ gerrit_user_name }}"
@@ -71,7 +71,7 @@
 
 - name: Write Gerrit secure config file
   template:
-    src: secure.config
+    src: secure.config.j2
     dest: "{{ gerrit_site_dir }}/etc/secure.config"
     owner: "{{ gerrit_user_name }}"
     group: "{{ gerrit_user_name }}"
@@ -83,8 +83,17 @@
     dest: "{{ gerrit_site_dir }}/etc/replication.config"
     owner: "{{ gerrit_user_name }}"
     group: "{{ gerrit_user_name }}"
+    mode: 0644
   when: gerrit_replication is defined
 
+- name: Write Gerrit JGit config
+  copy:
+    src: jgit.config
+    dest: "{{ gerrit_site_dir }}/etc/jgit.config"
+    owner: "{{ gerrit_user_name }}"
+    group: "{{ gerrit_user_name }}"
+    mode: 0644
+
 # Server host key for SSH service on port 29418
 - name: Write Gerrit SSH host private key
   copy:

playbooks/roles/gerrit/templates/gerrit.config.j2

@@ -74,7 +74,6 @@
 [receive]
 	maxObjectSizeLimit = 100 m
 	enableSignedPush = false
-	autogc = false
 [commentlink "bugheader"]
 	match = "([Cc]loses|[Pp]artial|[Rr]elated)-[Bb]ug:\\s*#?(\\d+)"
 	link = "https://launchpad.net/bugs/$2"