New ShutDownReceiver. Should correctly exit app when phone shut down. Related to #471

app/src/main/AndroidManifest.xml

@@ -403,6 +403,15 @@
                 <action android:name="android.intent.action.BOOT_COMPLETED"/>
             </intent-filter>
         </receiver>
+
+        <receiver
+            android:name="com.xabber.android.receiver.ShutDownReceiver">
+            <intent-filter>
+                <action android:name="android.intent.action.ACTION_SHUTDOWN"/>
+                <action android:name="android.intent.action.QUICKBOOT_POWEROFF" />
+            </intent-filter>
+        </receiver>
+
         <receiver android:name="com.xabber.android.receiver.GoAwayReceiver" />
         <receiver android:name="com.xabber.android.receiver.GoXaReceiver" />
         <receiver android:name="com.xabber.android.receiver.ComposingPausedReceiver" />

app/src/main/java/com/xabber/android/receiver/ShutDownReceiver.java

+package com.xabber.android.receiver;
+
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+
+import com.xabber.android.data.Application;
+
+public class ShutDownReceiver extends BroadcastReceiver {
+    @Override
+    public void onReceive(Context context, Intent intent) {
+        Application.getInstance().requestToClose();
+    }
+}