Remove / re-word some settings for WiFi-only devices.

Bug: 3468248

1. Remove Wireless->Mobile networks
2. Remove Wireless->Tethering and WiFi hotspot
3. Remove Wireless->Wi-Fi Settings->Wi-Fi disconnect policy
4. Re-word Network location summary text to not include "mobile network"

Change-Id: I84a551a1b63591974731029b0d4b90a85e43a716

src/com/android/settings/SecuritySettings.java

@@ -160,6 +160,11 @@ public class SecuritySettings extends SettingsPreferenceFragment
             mUseLocation = useLocation;
         }
 
+        // Change the summary for wifi-only devices
+        if (Utils.isWifiOnly()) {
+            mNetwork.setSummaryOn(R.string.location_neighborhood_level_wifi);
+        }
+
         // Add options for lock/unlock screen
         int resid = 0;
         if (!mLockPatternUtils.isSecure()) {