startActivityForResult with new Intent

Rather than use the raw Intent, we make a copy of it. See bug.

Bug: 330722900
Flag: EXEMPT bugfix
Test: manual
Test: atest com.android.settings.users.UserSettingsTest
            com.android.settings.users.UserDetailsSettingsTest
Change-Id: Id74e4b7ae261f2916eedaef04a679f83409a4b67