bug #2542580: add the appropriate mdpi asset for chat icon.

Change-Id: I474eb5b8fe83bbc7f92005de651444447c8624e7
diff --git a/core/res/res/drawable-mdpi/stat_notify_chat.png b/core/res/res/drawable-mdpi/stat_notify_chat.png
index 097a979..068b7ec 100644
--- a/core/res/res/drawable-mdpi/stat_notify_chat.png
+++ b/core/res/res/drawable-mdpi/stat_notify_chat.png
Binary files differ