[ios] Updated icons.

iphone/Maps/Images.xcassets/NavigationDashboard/ic_arrow_up_and_down.imageset/Contents.json

@@ -2,17 +2,17 @@
   "images" : [
     {
       "idiom" : "universal",
-      "filename" : "ic_arrow_up_and_down.png",
+      "filename" : "icArrowDown.png",
       "scale" : "1x"
     },
     {
       "idiom" : "universal",
-      "filename" : "ic_arrow_up_and_down@2x.png",
+      "filename" : "icArrowDown@2x.png",
       "scale" : "2x"
     },
     {
       "idiom" : "universal",
-      "filename" : "ic_arrow_up_and_down@3x.png",
+      "filename" : "icArrowDown@3x.png",
       "scale" : "3x"
     }
   ],