Update the logic to force cleanup all edit monitor instances.

Instead of checking the pidfiles, query all the running process with
binary ends with "edit_monitor" and kill all of those processes. This
ensures that if there are any unexpected edit monitor instances running
(e.g. due to b/382135550), the force cleanup can kill those processes as
well.

Bug: 382135550
Test: atest daemon_manager_test
Change-Id: I299f16b7b913e4ee470b5fe9ef0ffdad8d3c0945