The ResourceWatcherService enables watching of files for modifications
and deletions. During startup various consumers register the files that
should be watched by this service. There is behavior that might be
unexpected in that the service may not start polling until later in the
startup process due to the use of lifecycle states to control when the
service actually starts the jobs to monitor resources. This change
removes this unexpected behavior so that upon construction the service
has already registered its tasks to poll resources for changes. In
making this modification, the service no longer extends
AbstractLifecycleComponent and instead implements the Closeable
interface so that the polling jobs can be terminated when the service
is no longer required.
Relates #54867
Backport of #54993
2d9e3c7794