Move the job scheduler service code to its own jar file.

- Also remove the dependency from SystemServiceRegistry to JobScheduler

See apex/jobscheduler/README_js-mainline.md for the details.

Bug: 137763703
Test: build and boot
Test: atest CtsJobSchedulerTestCases
Change-Id: I2386c78b7a6085d6e543a63f22cb620c4cabd06a
diff --git a/config/preloaded-classes b/config/preloaded-classes
index 03e3b82..ea50999 100644
--- a/config/preloaded-classes
+++ b/config/preloaded-classes
@@ -563,6 +563,7 @@
 android.app.job.JobParameters$1
 android.app.job.JobParameters
 android.app.job.JobScheduler
+android.app.job.JobSchedulerFrameworkInitializer
 android.app.job.JobService$1
 android.app.job.JobService
 android.app.job.JobServiceEngine$JobHandler