Extend the ArtManager profiling API to cover boot image profiling

The boot image profile is available only on userdebug and eng builds and
combines the boot classpath and system server classpath.

Also, update ArtManager API to use Executors instead of Handlers.

Test: gts GtsAndroidRuntimeManagerHostTestCases
Bug: 30934496
Change-Id: Ie501947a659d644acbde04fb46157dd0c7944e81
5 files changed