BHV-12514: Ensure valid scroll position when picker is expanded.

Issue
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The scroll bounds can be invalid for `moon.IntegerPicker` controls expanded within a `moon.TimePicker`, causing unexpected scroll behavior initially. This is a side effect of the fix for BHV-11927 (https://github.com/enyojs/enyo/pull/806) as it assumes a valid value for the scroll bounds upon calling `scrollTo`.

Fix
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We stabilize the scroller when `refreshScrollState` in `moon.IntegerPicker` is called, which occurs when `moon.TimePicker` is expanded.

Enyo-DCO-1.1-Signed-off-by: Aaron Tam <aaron.tam@lge.com>