modify unread count style a bit.

rocket-chat-android-widgets/src/main/res/layout/room_list_item.xml

@@ -28,9 +28,10 @@
   <FrameLayout
       android:id="@+id/alert_count_container"
       android:layout_width="wrap_content"
+      android:minWidth="20dp"
       android:layout_height="wrap_content"
       android:layout_marginStart="8dp"
-      android:padding="8dp"
+      android:padding="4dp"
       android:layout_gravity="center_vertical"
       android:background="@color/room_list_item_unread_count_background"
       >
@@ -39,6 +40,7 @@
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:textSize="12dp"
+        android:layout_gravity="center"
         android:textAppearance="@style/TextAppearance.AppCompat.Body1"
         />
   </FrameLayout>