Extract ChooserActivity "content preview" logic.

This is sort of a crude first pass at pulling out a batch of related
methods with a similar overall structure that's reasonably
self-contained (modulo the new delegate interfaces introduced in this
CL). No attempt was made at introducing new abstractions for the
preview; this follows the factory methods that were already present
in ChooserActivity. Other methods that remain in ChooserActivity may
be better fit for migration to the new component, pending further
design work that's out-of-scope for this CL.

Test: atest IntentResolverUnitTests
Bug: 202167050
Change-Id: Ieacffb3d184e60609a1a5e75542358a765e59ae3
5 files changed