The conversion of EchoEvent into a EchoEventPresentationModel is now
done by EchoFlyoutFormatter, instead of having each subclass do it. It
also does the canRender() check so subclasses don't need to worry about
it.
The subclasses no longer have access to the underlying EchoEvent object,
so the timestamp is exposed in EchoEventPresentationModel.
Change-Id: I7f0a650373eebac7aa2231b1795b51a6d031ad67
The workflow to format a notification is
* Get EchoEvent, User, and Language
* Get EchoEventFormatter implementation for notification type
** EchoEventFormatter returns structured data about each part of the
notification (header, body, primary link, secondary link(s))
* Each output type will have a formatter class (e.g.
EchoSpecialNotificationsFormatter, EchoPlainTextEmailFormatter) which
takes a EchoEventPresentationModel and generates whatever it wants
(HTML, plain-text email, etc).
Included is an example conversion of the user-rights and mention
formatters. The previous infrastructure will remain in place for
backwards compatability until other extensions can be updated.
Bug: T107823
Change-Id: I4397872a7ec062148dfcb066ddd8ab83f40486ac
