Fix regression in recent task list replacement

- Accidentally removed a user check in ag/3762067 when adding the check for
  compatible activity types :(. Added it back and a test to ensure that we
  don't remove tasks that are otherwise identical except belong to
  different users.

Bug: 77661783
Test: atest FrameworksServicesTests:RecentTasksTest
Change-Id: I9a0ec8f62e85e89f97dce615252b4c7635f505f8