BHV-6842: [DataListSample] Allow for Scroll to Index function to be reused when list is not scrolled.

Issue
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A previous fix to allow the `Scroll to Index` feature of the `DataListSample` to function when the list had been scrolled introduced a regression where the `Scroll to Index` feature could not be reused unless scrolling had occurred.

Fix
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We now allow the `scrollToIndex` method to be called when either scrolling has occurred, or if the current index differs than the desired index.

Enyo-DCO-1.1-Signed-off-by: Aaron Tam <aaron.tam@lge.com>