Bugfix: Public API stop does not start service in foreground.

Fixes #1354.

src/main/java/de/dennisguse/opentracks/publicapi/AbstractAPIActivity.java

@@ -34,7 +34,7 @@ public abstract class AbstractAPIActivity extends AppCompatActivity {
         if (PreferencesUtils.isPublicAPIenabled()) {
             Log.i(TAG, "Received and trying to execute requested action.");
             new TrackRecordingServiceConnection(serviceConnectedCallback)
-                    .startAndBind(this, true);
+                    .startAndBind(this, isStartServiceForeground());
         } else {
             Toast.makeText(this, getString(R.string.settings_public_api_disabled_toast), Toast.LENGTH_LONG).show();
             Log.w(TAG, "Public API is disabled; ignoring request.");
@@ -42,6 +42,10 @@ public abstract class AbstractAPIActivity extends AppCompatActivity {
         }
     }
 
+    protected boolean isStartServiceForeground() {
+        return false;
+    }
+
     protected abstract void execute(TrackRecordingService service);
 
     protected abstract boolean isPostExecuteStopService();

src/main/java/de/dennisguse/opentracks/publicapi/StartRecording.java

@@ -57,4 +57,9 @@ public class StartRecording extends AbstractAPIActivity {
     protected boolean isPostExecuteStopService() {
         return false;
     }
+
+    @Override
+    protected boolean isStartServiceForeground() {
+        return true;
+    }
 }