More fallout of merge in GameActivity

- added GameApplication, network change notifications, Firebase, and lifecycle

#android
#rb Pete.Procopio


#ROBOMERGE-OWNER: ryan.gerleve
#ROBOMERGE-AUTHOR: chris.babcock
#ROBOMERGE-SOURCE: CL 5232162 via CL 5238945 via CL 5239022
#ROBOMERGE-BOT: ENGINE (Main -> Dev-Networking)

[CL 5255241 by chris babcock in Dev-Networking branch]

Engine/Build/Android/Java/src/com/epicgames/ue4/GameActivity.java.template

@@ -174,8 +174,6 @@ import com.epicgames.ue4.GooglePlayLicensing;
 // Console commands listener, only for debug builds
 import com.epicgames.ue4.ConsoleCmdReceiver;
 
-import com.epicgames.ue4.MultiChannelMediaEncoder;
-
 import android.os.Build;
 
 // TODO: use the resources from the UE4 lib project once we've got the packager up and running

Engine/Build/Android/Java/src/com/epicgames/ue4/GameApplication.java.template

@@ -0,0 +1,48 @@
+package com.epicgames.ue4;
+
+import android.app.Application;
+import android.arch.lifecycle.Lifecycle;
+import android.arch.lifecycle.LifecycleObserver;
+import android.arch.lifecycle.OnLifecycleEvent;
+import android.arch.lifecycle.ProcessLifecycleOwner;
+
+import com.epicgames.ue4.network.NetworkChangedManager;
+//$${gameApplicationImportAdditions}$$
+
+public class GameApplication extends Application implements LifecycleObserver {
+	private static final Logger Log = new Logger("UE4-" + GameApplication.class.getSimpleName());
+	public static final String MESSAGING_CONFIG = "messaging";
+
+	private static boolean isForeground = false;
+
+	@Override
+	public void onCreate() {
+		super.onCreate();
+//$${gameApplicationOnCreateAdditions}$$
+
+		ProcessLifecycleOwner.get().getLifecycle().addObserver(this);
+
+		NetworkChangedManager.getInstance().initNetworkCallback(this);
+	}
+
+	@OnLifecycleEvent(Lifecycle.Event.ON_START)
+	void onEnterForeground() {
+		Log.verbose("App in foreground");
+		isForeground = true;
+	}
+
+	@OnLifecycleEvent(Lifecycle.Event.ON_STOP)
+	void onEnterBackground() {
+		Log.verbose("App in background");
+		isForeground = false;
+	}
+
+	@SuppressWarnings("unused")
+	public static boolean isAppInForeground() {
+		return isForeground;
+	}
+
+	public static boolean isAppInBackground() {
+		return !isForeground;
+	}
+}

Engine/Build/Android/Java/src/com/epicgames/ue4/network/NetworkChangedListener.java

@@ -0,0 +1,10 @@
+package com.epicgames.ue4.network;
+
+import android.net.Network;
+
+public interface NetworkChangedListener {
+	
+	void onNetworkAvailable(Network network);
+
+	void onNetworkLost(Network network);
+}

Engine/Build/Android/Java/src/com/epicgames/ue4/network/NetworkChangedManager.java

@@ -0,0 +1,86 @@
+package com.epicgames.ue4.network;
+
+import android.content.Context;
+import android.net.ConnectivityManager;
+import android.net.Network;
+import android.net.NetworkRequest;
+import android.support.annotation.NonNull;
+
+import com.epicgames.ue4.Logger;
+
+import java.lang.ref.WeakReference;
+import java.util.HashSet;
+import java.util.Set;
+
+public final class NetworkChangedManager {
+
+	private static final Logger Log = new Logger("UE4-NetworkChangedManager");
+	private static final String SYSTEM = "NetworkManager";
+	private static final String COMPONENT = "ConnectivityManager";
+	private static final String ACTION_ERROR = "InstanceNotAvailable";
+
+	private static NetworkChangedManager instance;
+
+	@NonNull
+	private Set<WeakReference<NetworkChangedListener>> networkChangedListeners = new HashSet<>();
+
+	@NonNull
+	public static synchronized NetworkChangedManager getInstance() {
+		if (instance == null) {
+			instance = new NetworkChangedManager();
+		}
+		return instance;
+	}
+
+	private NetworkChangedManager() {
+	}
+
+	public void initNetworkCallback(@NonNull Context context) {
+		ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
+		if (connectivityManager != null) {
+			NetworkRequest.Builder builder = new NetworkRequest.Builder();
+			connectivityManager.registerNetworkCallback(
+				builder.build(),
+				new ConnectivityManager.NetworkCallback() {
+					@Override
+					public void onAvailable(Network network) {
+						Log.verbose("Network Available");
+						for (WeakReference<NetworkChangedListener> listenerWeakRef : networkChangedListeners) {
+							NetworkChangedListener listener = listenerWeakRef.get();
+							if (listener != null) {
+								listener.onNetworkAvailable(network);
+							} else {
+								removeListener(listenerWeakRef);
+							}
+						}
+					}
+
+					@Override
+					public void onLost(Network network) {
+						Log.verbose("Network Lost");
+						for (WeakReference<NetworkChangedListener> listenerWeakRef : networkChangedListeners) {
+							NetworkChangedListener listener = listenerWeakRef.get();
+							if (listener != null) {
+								listener.onNetworkLost(network);
+							} else {
+								removeListener(listenerWeakRef);
+							}
+						}
+					}
+				}
+			);
+		} else {
+			Log.error("Unable to start connectivityManager");
+		}
+	}
+
+	@SuppressWarnings({"unused", "UnusedReturnValue"})
+	public boolean addListener(WeakReference<NetworkChangedListener> listener) {
+		return networkChangedListeners.add(listener);
+	}
+
+	@SuppressWarnings({"unused", "UnusedReturnValue"})
+	public boolean removeListener(WeakReference<NetworkChangedListener> listener) {
+		return networkChangedListeners.remove(listener);
+	}
+}