Add --overlay option in charmed installer

Change-Id: I99e2e8a27f7a930380a2fa686e2352b8fea69c7e
Signed-off-by: David Garcia <david.garcia@canonical.com>
diff --git a/installers/full_install_osm.sh b/installers/full_install_osm.sh
index 57cc4fb..42c2ed5 100755
--- a/installers/full_install_osm.sh
+++ b/installers/full_install_osm.sh
@@ -77,6 +77,7 @@
     echo -e "     [--lxd <yaml path>]:         Takes a YAML file as a parameter with the LXD Cloud information (--charmed option)"
     echo -e "     [--lxd-cred <yaml path>]:    Takes a YAML file as a parameter with the LXD Credentials information (--charmed option)"
     echo -e "     [--microstack]:              Installs microstack as a vim. (--charmed option)"
+    echo -e "     [--overlay]:                 Add an overlay to override some defaults of the default bundle (--charmed option)"
     echo -e "     [--ha]:                      Installs High Availability bundle. (--charmed option)"
     echo -e "     [--tag]:                     Docker image tag. (--charmed option)"
     echo -e "     [--registry]:                Docker registry with optional credentials as user:pass@hostname:port (--charmed option)"
@@ -1824,6 +1825,7 @@
             [ "${OPTARG}" == "lxd" ] && continue
             [ "${OPTARG}" == "lxd-cred" ] && continue
             [ "${OPTARG}" == "microstack" ] && continue
+            [ "${OPTARG}" == "overlay" ] && continue
             [ "${OPTARG}" == "only-vca" ] && continue
             [ "${OPTARG}" == "vca" ] && continue
             [ "${OPTARG}" == "ha" ] && continue