feat: running foreground service on mobile (#261)

ui/flutter/android/app/build.gradle

@@ -47,7 +47,7 @@ android {
         applicationId "com.gopeed"
         // You can update the following values to match your application needs.
         // For more information, see: https://docs.flutter.dev/deployment/android#reviewing-the-build-configuration.
-        minSdkVersion 19
+        minSdkVersion 21
         targetSdkVersion 29
         versionCode flutterVersionCode.toInteger()
         versionName flutterVersionName

ui/flutter/android/app/src/main/AndroidManifest.xml

@@ -72,6 +72,12 @@
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
+
+        <!-- Add android:stopWithTask option only when necessary. -->
+        <service 
+            android:name="com.pravera.flutter_foreground_task.service.ForegroundService"
+            android:stopWithTask="true" />
+
         <!-- Don't delete the meta-data below.
              This is used by the Flutter tool to generate GeneratedPluginRegistrant.java -->
         <meta-data