Refactor ChooserRequestParameters usage

Creates ChooserRequest data class
Uses validation lib to implement parsing of source data

Introduces ChooserViewModel as a new target to begin migration of
control flow, data and dependencies out of ChooserActivity and into
smaller testable units.

Test: atest IntentResolver-tests-activity:com.android.intentresolver.v2
Bug: 309960444
Change-Id: I39b3517ec9e17525441d349b3da139ad5956c600