BHV-17980: update _marquee_contentChanged() for text align of marquee te...

##Issue 
In the RTL mode, text align should be right. But, during the marquee flow, marquee text has "text-align:left". At that time, if developer change the content dynamically to short text, the text align to left.(Expected alignment is right)

##Fix
Update _marquee_contentChanged function to apply proper text-align of the text
Since content is already changed, initialize _marquee_distance and _marquee_fits by calling _marquee_invalidateMetrics()

Enyo-DCO-1.1-Signed-off-by: Sungbae Cho sb.cho@lge.com