unify border radius, so chat bubbles respect it too

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

app/src/main/res/values/dimens.xml

@@ -37,8 +37,8 @@
     <dimen name="avatar_size_big">96dp</dimen>
 
     <dimen name="chat_text_size">14sp</dimen>
-    <dimen name="message_bubble_corners_radius">6dp</dimen>
-    <dimen name="message_bubble_corners_padding">8dp</dimen>
+    <dimen name="message_bubble_corners_radius">@dimen/dialogBorderRadius</dimen>
+    <dimen name="message_bubble_corners_padding">16dp</dimen>
 
     <dimen name="geocoding_result_text_size">18sp</dimen>