Slight adjustments to bubble bar education view values

Need to apply the padding to the text view, BubblePopupViewExt sets
its own padding to account for the carrot so the bottom padding
was getting overridden. Setting it on the text view ensures it's
correct.

Also missed setting one colour!

Flag: com.android.wm.shell.enable_bubble_bar
Test: manual - enable user education and inspect the views
Bug: 372516663
Change-Id: I3db8c4fcaa0006f49af26ce0359ec58ab08525c3