JobScheduler: Add evaluation patch for detecting and logging empty jobs

This patch implements a low-risk evaluation to detect and log empty jobs
via tracing within the job scheduler service. It uses a new hidden API
in IJobCallback.aidl. The atrace trace, combined with
ScheduledJobStateChanged, will help analyze empty job characteristics.

Bug: 349688611
Flag: android.app.job.cleanup_empty_jobs
Test: Existing CTS and unit tests pass. Ran a test JobScheduler app and
checked the perfetto trace for empty jobs

Change-Id: I3261bd14be7f62be664a31a4dfb9baf044c33957