ENYO-874: Settings app has a problem of not showing scroller content under fittable layout
ENYO-874: Settings app has a problem of not showing scroller content under fittable layout

Issue:
There is a chance to set fittable set height as 0 on pushPanel.
- pushPanel is create a panel, render, reflow panels, resize, setIndex
- reflow can change new panel showing property as false
- following resize always fail, so set height to 0
Problem happens when setIndex fails to set valid height

Fix:
- We can remove the chance of set height 0 on panel resize
- So that we can show valid height even if we fail to reflow on following setIndex

DCO-1.1-Signed-Off-By: Kunmyon Choi kunmyon.choi@lge.com

mcanthony/moonstone,enyojs/moonstone,mcanthony/moonstone,mcanthony/moonstone