Add callback for notifying that startup is completed

Add a callback that can be called to denote that application startup
is completed. This may affect how the profile is collected and how
startup related caches are managed.

Bug: 123377072
Bug: 120671223
Test: test-art-host
Change-Id: Ia317627614566c3060e3c2e246bfb01f6b4f750a
2 files changed