Remove send message gravity for RtL

Change-Id: I6ef122632a2c098054babad2baaa6cd338dc96b8
Locate the timestamps outside of bubbles

Change-Id: Ib6739976a65333a908027b5a88cd848f3459fe01

Conflicts:

	res/layout/message_list_item_recv_bubbles.xml
	res/layout/message_list_item_send_bubbles.xml
Shrink the minimum bubble size

Change-Id: Ib0845f0315620e2961ab9312e80ff9b7cb5649f6