Fixed commit list system not gradient

Merged Phil Hughes requested to merge system-note-commits-list-gradient-fix into master

What does this MR do?

Fixes the commit system note list gradient not being tall enough for the text. Also fixes an issue with the gradient when the note is the current target.

Screenshots (if relevant)

Screen_Shot_2017-06-20_at_14.31.37

Screen_Shot_2017-06-20_at_14.31.40

What are the relevant issue numbers?

Closes #33896 (closed)