change dark theme background to #121212

see https://material.io/design/color/dark-theme.html#properties

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

src/main/res/values-night/colors.xml

@@ -25,7 +25,7 @@
     <color name="list_divider_background">#222222</color>
 
     <!-- Colors -->
-    <color name="bg_default">#151515</color>
+    <color name="bg_default">#121212</color>
     <color name="fg_contrast">#717171</color>
     <color name="primary_button_text_color">#000000</color>