Remove direct-share target row animations and limit to one row.

The animation---which was responsible for causing relayouts
that would in turn bind views, which involved package
manager roundtrips---would lock out interaction with the rest of
the share sheet for at least 400ms while the animation ran
(often much longer if services were slow to start or respond).

Now the main UI is never blocked, and direct share targets
can take as long as they like (up to 2sec) before appearing.

It's really fast now, basically.

Bug: 67622422
Bug: 63521992
Test: atest com.android.internal.app.ChooserActivityTest
Change-Id: I21826e282226f2b2ce6d3d1b5862dbfc449f5918