Fix up bubble images from experimental bubbles

* If we're using the small icon make sure to tint it
* If there's a person try to use the icon from message style layout, this
  requires us to add the bubble after the notification has been inflated by
  changing onPendingEntryAdded to onNotificationAdded, this should
  be fine for bubbles / no big difference between these.

Bug: 146233974
Test: atest BubbleControllerTest
Test: manual:
      1) create bubble from telegram user without an image
      => observe that the image looks like what's in the notification
      2) create bubble from snapchat
      => observe that the small notification icon is used & tinted
Change-Id: I67c70619824912b2cbcbcb21df6cd219cc8796c0