move setLastFocusedChild to Scroller from ScrollStrategy

CMB-1706 moved spotlight container back to scroller but this was missed

Issue: BHV-15492
Enyo-DCO-1.1-Signed-off-by: Ryan Duffy (ryan.duffy@lge.com)
Merge pull request #1709 from enyojs/BHV-15492-ryanjduffy

Fixes BHV-15492

Reviewed-By: Krishna Rangarajan (krishna.rangarajan@lge.com)
Integrated-By: Aaron Tam (aaron.tam@lge.com)