Resolves #206, enables predictive back navigation support

Author: YuraLaguta

app/src/main/AndroidManifest.xml

@@ -22,6 +22,7 @@
     <application
         android:name=".NiaApplication"
         android:allowBackup="true"
+        android:enableOnBackInvokedCallback="true"
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
         android:roundIcon="@mipmap/ic_launcher_round"