Fix issue #3272051: Use backward transition when going backwards.

Also know as:

Issue #3272051 Contacts edit view: Tapping the in-app back button
results in a forward transition

Yeah more complexity in deciding which animation to use.

Also reduce complexity in deciding which app's animation set to use,
to balance things out (and make it have less stupid behavior).

Change-Id: I78c6c5c5249a96206f7e03ce587c1dcb9a7dc14f