Cherry-pick #16476 to 7.x: match reference.yml to code default (#16484)

(cherry picked from commit 523528b)

Co-authored-by: Dan Roscigno <dan@roscigno.com>

libbeat/_meta/config.reference.yml.tmpl

@@ -973,10 +973,10 @@ setup.template.settings:
 # to load your own lifecycle policy.
 #setup.ilm.policy_file:
 
-# Disable the check for an existing lifecycle policy. The default is false. If
+# Disable the check for an existing lifecycle policy. The default is true. If
 # you disable this check, set setup.ilm.overwrite: true so the lifecycle policy
 # can be installed.
-#setup.ilm.check_exists: false
+#setup.ilm.check_exists: true
 
 # Overwrite the lifecycle policy at startup. The default is false.
 #setup.ilm.overwrite: false