Missing changes from fork CL ag/20001357.

This is essentially porting the set of framework changes that either
weren't synced to my local client at the time that the fork CL was
cut, or else were merged only to framework since then, and not yet
ported to IntentResolver. (Any future changes to framework Chooser
should, hopefully, be accompanied by the parallel port CL at the time
of submission.)

This CL was constructed by a mostly-manual process:

 1. Review the history of all framework changes under
    ../core/internal/app and ../core/internal/widget for changes in
    any files that have been ported to IntentResolver, and apply those
    diffs to the forked files (keeping in mind that each of these CLs
    could expand the scope beyond files that had been forked to-date).
    Also briefly review history in framework resources (no changes
    appear to be related to Chooser).

 2. Review the set of diffs between relative paths in the
    IntentResolver package and the corresponding path resolved in the
    framework(*) to observe/enforce the expected set from ag/20001357
    (effectively manually rolling back IntentResolver changes since
    fork; probably would've been better as a setup step, but:)

 3. Manually re-apply IntentResolver-only changes that have been
    merged since the fork.

 4. Review diffs in the IntentResolver package (i.e., this CL) to
    ensure that they're attributable to changes encountered in [1].

 5. Fix (pre-existing) lint errors in the changed files (only caught
    by presubmits after this CL was otherwise ready to upload / still
    good to address while we're here.) Re-build/test.

Test: atest IntentResolverUnitTests
Bug: 202166832

Change-Id: I23f4d4e763072abd0e9a4bb2d61fefc5f6b39830
8 files changed