Use viewmodels with LiveData.

app/src/main/AndroidManifest.xml

@@ -11,6 +11,11 @@
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
         android:theme="@style/AppTheme">
+        <service
+            android:name=".Tichu"
+            android:enabled="true"
+            android:exported="true"></service>
+
         <activity
             android:name=".MainActivity"
             android:exported="true"
@@ -22,6 +27,7 @@
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
+
         <service
             android:name="androidx.appcompat.app.AppLocalesMetadataHolderService"
             android:enabled="false"