Fix message list pressed state color

Also do some cleanup - we were creating a background task for opening a
message, when in the common case we don't need to hit disk for any
reason. This was also an issue since the async opening of the message
caused the list item to go into an "active" state, changing its colour
(this problem still exists in starred view now, though)

Bug: 5222509
Change-Id: Ie94109df42406fd6eec1e1255bb0827626ba0628
2 files changed