Require user id when checking multi-instance support

- Ensure that we check the application/activity property for the given
  user as there may be packages that are enabled for another user but
  is not installed for the primary user
- Also add a shell command to dump information in the system about
  which packages & components have declared the property

Bug: 391611065
Flag: EXEMPT bugfix
Test: atest WMShellUnitTests
Test: Install a multi-instance supported app for the non-primary user,
      ensure that we can still invoke multiple instances of it

Change-Id: I9d38f32aa38b27b2bffaa744c3f578423f7c7d86