Support restart in daemon manager

The daemon manager will restart periodically based on the current binary
file. If the edit monitor binary no longer exists (e.g. user has deleted
the corresponding Android source tree) when a restart is triggered, the edit monitor will just exit directly.

Test: atest daemon_manager_test
bug: 365617369
Change-Id: If36ca056c6a45868b5b1f722c07eb2891928e85b