Instrument PM classes with @Watched

Bug: 179388643

Annotate more PackageManagerService classes with the @Watched
attribute.

Test: atest
 * FrameworksServicesTests:UserSystemPackageInstallerTest
 * FrameworksServicesTests:PackageManagerSettingsTests
 * FrameworksServicesTests:PackageManagerServiceTest
 * FrameworksServicesTests:AppsFilterTest
 * FrameworksServicesTests:PackageInstallerSessionTest
 * FrameworksServicesTests:ScanTests
 * UserLifecycleTests#startUser
 * UserLifecycleTests#stopUser
 * UserLifecycleTests#switchUser
 * android.appsecurity.cts.EphemeralTest#testEphemeralStartExposed06
 * android.appsecurity.cts.InstantAppUserTest#testStartExposed06

Change-Id: Iab2da530786a0abc91d356da8e1bbd4c824f0333