Start user in background via adb command instead of calling the API.

If the user to be started is a profile of a current foreground user,
it should be started via IActivityManager.startProfileWithListener API
instead of IActivityManager.startUserInBackgroundWithListener. This
logic is already implemented in ActivityManagerShellCommand, so rather
than duplicating it, we'll be doing it by running the shell command.

Bug: 279403644
Test: atest UserLifecycleTests
Change-Id: I4b9e6f1e565187e93e13ad94f41d51ee5f7e3e42