Prioritize Smart Actions over Smart Replies.

Up until now we've added Smart Replies and Actions prioritizing Replies
over Actions (because Replies show up before / to the left of Actions in
the UI). With this CL we prioritize adding Smart Actions over adding
Smart Replies.

Bug: 119010281
Test: atest SmartReplyViewTest
Test: manual, using cinek@'s Notify app: ensure if there are enough
smart actions to fill the notification view, no smart replies are added.

Change-Id: Ia413d6a9d3cf04cfb0dcad2df560aa0dd1660287