[TIMOB-13422] iOS: ListView: Listview sample shows grey color on list item under certain circumstances

Description:

While testing Kitchensink on iOS, I noticed that some of the listview items had a grey bar appearing when using the listview. They color is being set when checking the white scroll indicator (the color is set darker to be able to see the white scroll indicator), but is not reset when changing back to the black or default scroll indicator where the list view items are on a white background. See screenshot

Steps to reproduce:

1) Install KS from master branch of https://github.com/appcelerator-developer-relations/KitchenSink 2) Navigate to base UI > Views > List View > Scroll style 3) Select "Style White" 4) Select "Style Black" 5) Select any one of the "Item" list view items

Result:

The Style Black item row is still grey. This may not occur 100% of the time.

Expected Result:

All rows have uniform coloring and attributes