Glusterfs: use automatic mtime-based split-brain resolution

Change-Id: I9975d30dd57721a8703d4144ba3d6c1909a789c1
diff --git a/glusterfs/server/volume/mysql.yml b/glusterfs/server/volume/mysql.yml
index 0e7367c..c473de6 100644
--- a/glusterfs/server/volume/mysql.yml
+++ b/glusterfs/server/volume/mysql.yml
@@ -14,4 +14,5 @@
             nfs.disable: On
             network.remote-dio: On
             diagnostics.client-log-level: WARNING
-            diagnostics.brick-log-level: WARNING
\ No newline at end of file
+            diagnostics.brick-log-level: WARNING
+            cluster.favorite-child-policy: mtime