Cros: Fix long press highlight to correct color

Bug: 1049273
Change-Id: I8e01516825cf26118e454ed640884fcc6f365ecf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2071035
Commit-Queue: Ana Salazar <anasalazar@chromium.org>
Commit-Queue: Alex Newcomer <newcomer@chromium.org>
Reviewed-by: Alex Newcomer <newcomer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#744096}

ash/app_list/views/app_list_item_view.cc

@@ -71,7 +71,8 @@ constexpr SkColor kFolderGridTitleColor = SK_ColorBLACK;
 constexpr SkColor kFolderGridFocusRingColor = gfx::kGoogleBlue600;
 
 // The color of an item selected via right-click context menu.
-constexpr SkColor kContextSelection = SkColorSetA(gfx::kGoogleGrey100, 31);
+constexpr SkColor kContextSelection =
+    SkColorSetA(SK_ColorWHITE, 41);  // 16% opacity
 
 // The color of an item selected via right-click context menu in a folder.
 constexpr SkColor kContextSelectionFolder =