minor updates on styles and improve code conciseness.

Author: johnnzhou

app/src/main/java/com/lcl/lclmeasurementtool/MainActivity.java

@@ -33,11 +33,11 @@ public class MainActivity extends AppCompatActivity {
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
-        mNetworkManager = NetworkManager.getManager(this);
-        mCellularManager = CellularManager.getManager(this);
-        mLocationManager = LocationServiceManager.getManager(this);
+        mNetworkManager = NetworkManager.getManager(this.getApplicationContext());
+        mCellularManager = CellularManager.getManager(this.getApplicationContext());
+        mLocationManager = LocationServiceManager.getManager(this.getApplicationContext());
 
-        locationServiceListener = new LocationServiceListener(this, getLifecycle());
+        locationServiceListener = new LocationServiceListener(this.getApplicationContext(), getLifecycle());
         getLifecycle().addObserver(locationServiceListener);
 
         TextView tv = (TextView) findViewById(R.id.signalStrengthStatus);

app/src/main/java/com/lcl/lclmeasurementtool/Managers/LocationServiceManager.java

@@ -56,7 +56,7 @@ private LocationServiceManager(@NonNull Context context) {
      */
     public static LocationServiceManager getManager(@NonNull Context context) {
         if (locationServiceManager == null) {
-            locationServiceManager = new LocationServiceManager(context.getApplicationContext());
+            locationServiceManager = new LocationServiceManager(context);
         }
         return locationServiceManager;
     }

app/src/main/java/com/lcl/lclmeasurementtool/Managers/NetworkManager.java

@@ -34,7 +34,7 @@ public class NetworkManager {
     private ConnectivityManager.NetworkCallback networkCallback;
 
     // the connectivity manager object that keeps track of all information
-    // related to phone's connectivyt states.
+    // related to phone's connectivity states.
     private final ConnectivityManager connectivityManager;
 
     // current device supports with regards to networking.
@@ -59,7 +59,6 @@ private NetworkManager(@NonNull Context context) {
      * @return a network manager
      */
     public static NetworkManager getManager(@NonNull Context context) {
-
         if (networkManager == null) {
             networkManager = new NetworkManager(context);
         }
@@ -121,7 +120,7 @@ public void onUnavailable() {
      *
      * @param networkChangeListener the listener to be removed (should not be null)
      */
-    public void removeNetworokChangeListener(@NonNull NetworkChangeListener networkChangeListener) {
+    public void removeNetworkChangeListener(@NonNull NetworkChangeListener networkChangeListener) {
         mNetworkChangeListeners.remove(networkChangeListener);
     }