improve notification icon dark theming

Signed-off-by: Andy Scherzinger <info@andy-scherzinger.de>

src/main/java/com/owncloud/android/ui/adapter/NotificationListAdapter.java

@@ -20,7 +20,10 @@
 package com.owncloud.android.ui.adapter;
 
 import android.content.Intent;
+import android.content.res.Configuration;
 import android.content.res.Resources;
+import android.graphics.Color;
+import android.graphics.PorterDuff;
 import android.graphics.Typeface;
 import android.graphics.drawable.PictureDrawable;
 import android.net.Uri;
@@ -135,11 +138,17 @@ public class NotificationListAdapter extends RecyclerView.Adapter<NotificationLi
 
         holder.message.setText(notification.getMessage());
 
-        // Todo set proper action icon (to be clarified how to pick)
         if (!TextUtils.isEmpty(notification.getIcon())) {
             downloadIcon(notification.getIcon(), holder.icon);
         }
 
+        int nightModeFlag = notificationsActivity.getResources().getConfiguration().uiMode & Configuration.UI_MODE_NIGHT_MASK;
+            if (Configuration.UI_MODE_NIGHT_YES == nightModeFlag) {
+                holder.icon.setColorFilter(Color.WHITE, PorterDuff.Mode.SRC_IN);
+            } else {
+                holder.icon.setColorFilter(Color.BLACK, PorterDuff.Mode.SRC_IN);
+            }
+
         setButtons(holder, notification);
 
         holder.dismiss.setOnClickListener(v -> new DeleteNotificationTask(client, notification, holder,

src/main/res/layout/notification_list_item.xml

@@ -38,7 +38,6 @@
         android:layout_marginEnd="@dimen/notification_icon_layout_right_end_margin"
         android:padding="2dp"
         android:alpha="0.5"
-        android:background="@drawable/round_bgnd_icons"
         android:contentDescription="@string/notification_icon"
         android:src="@drawable/ic_notification" />