MDEV-36531 Enable Feedback Plugin for DEB Packages

debian/mariadb-server.postinst

@@ -242,6 +242,23 @@ EOF
     chown 0:0 $dc
     chmod 0600 $dc
 
+    feedback_cnf=$mariadb_cfgdir/mariadb.conf.d/feedback.cnf
+    if [ ! -f $feedback_cnf ]; then
+      if db_input high mariadb-server/feedback_optin; then
+        db_go || true
+      fi
+      db_get mariadb-server/feedback_optin
+      {
+        echo "# THIS IS A GENERATED FILE. ALL CHANGES TO IT MIGHT BE LOST.";
+        echo "[server]";
+        if [ "$RET" = true ]; then
+          echo "feedback=ON";
+        else
+          echo "feedback=OFF";
+        fi
+      } >> $feedback_cnf
+    fi
+
     # If there is a real AppArmor profile, we reload it.
     # If the default empty profile is installed, then we remove any old
     # profile that may be loaded.

debian/mariadb-server.templates

@@ -43,3 +43,12 @@ _Description: Remove all MariaDB databases?
  If you're removing the MariaDB package in order to later install a more
  recent version or if a different mariadb-server package is already
  using it, the data should be kept.
+
+Template: mariadb-server/feedback_optin
+Type: boolean
+Default: false
+_Description: Enable the Feedback plugin and submit anonymous usage information?
+ Feedback plugin collects basic anonymous statistical information that can be
+ used by the developers to improve MariaDB. This is an easy way to help with
+ MariaDB development. Collected statistics can be viewed at
+ http://mariadb.org/feedback-plugin