shill: WiFi:  Allow HiddenSSID to be settable

Allow this parameter to be settable, so ONC can configure a
visible network to be hidden if it is not and vice versa.

BUG=chromium:149132
TEST=Unit tests

Change-Id: Icf32120356973c2331ce2f448a957fcbffe94a87
Reviewed-on: https://gerrit.chromium.org/gerrit/33263
Reviewed-by: mukesh agrawal <quiche@chromium.org>
Commit-Ready: Paul Stewart <pstew@chromium.org>
Tested-by: Paul Stewart <pstew@chromium.org>
diff --git a/wifi_service.cc b/wifi_service.cc
index f131874..f6700f8 100644
--- a/wifi_service.cc
+++ b/wifi_service.cc
@@ -76,7 +76,7 @@
   store->RegisterConstString(flimflam::kSecurityProperty, &security_);
 
   store->RegisterConstString(flimflam::kWifiAuthMode, &auth_mode_);
-  store->RegisterConstBool(flimflam::kWifiHiddenSsid, &hidden_ssid_);
+  store->RegisterBool(flimflam::kWifiHiddenSsid, &hidden_ssid_);
   store->RegisterConstUint16(flimflam::kWifiFrequency, &frequency_);
   store->RegisterConstUint16(flimflam::kWifiPhyMode, &physical_mode_);
   store->RegisterConstString(flimflam::kWifiBSsid, &bssid_);
@@ -120,7 +120,6 @@
   IgnoreParameterForConfigure(flimflam::kSSIDProperty);
   IgnoreParameterForConfigure(flimflam::kSecurityProperty);
   IgnoreParameterForConfigure(flimflam::kPassphraseProperty);
-  IgnoreParameterForConfigure(flimflam::kWifiHiddenSsid);
 }
 
 WiFiService::~WiFiService() {}