use wifi info only for 2 funcs

android/src/main/java/com/learnium/RNDeviceInfo/RNDeviceModule.java

@@ -40,10 +40,6 @@ public class RNDeviceModule extends ReactContextBaseJavaModule {
     super(reactContext);
 
     this.reactContext = reactContext;
-
-
-    WifiManager manager = (WifiManager) reactContext.getSystemService(Context.WIFI_SERVICE);
-    this.wifiInfo = manager.getConnectionInfo();
   }
 
   @Override
@@ -51,6 +47,14 @@ public class RNDeviceModule extends ReactContextBaseJavaModule {
     return "RNDeviceInfo";
   }
 
+  private WifiInfo getWifiInfo() {
+    if ( this.wifiInfo == null ) {
+      WifiManager manager = (WifiManager) reactContext.getSystemService(Context.WIFI_SERVICE);
+      this.wifiInfo = manager.getConnectionInfo();
+    }
+    return this.wifiInfo;
+  }
+
   private String getCurrentLanguage() {
       Locale current = getReactApplicationContext().getResources().getConfiguration().locale;
       if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
@@ -95,13 +99,13 @@ public class RNDeviceModule extends ReactContextBaseJavaModule {
 
   @ReactMethod
   public void getIpAddress(Promise p) {
-    String ipAddress = Formatter.formatIpAddress(wifiInfo.getIpAddress());
+    String ipAddress = Formatter.formatIpAddress(getWifiInfo().getIpAddress());
     p.resolve(ipAddress);
   }
 
   @ReactMethod
   public void getMacAddress(Promise p) {
-    String macAddress = wifiInfo.getMacAddress();
+    String macAddress = getWifiInfo().getMacAddress();
     p.resolve(macAddress);
   }