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: If7eb8909cc5e99082a2243b5029380244b46174d
diff --git a/test/knownfailures.json b/test/knownfailures.json
index 927817a..6a41daf 100644
--- a/test/knownfailures.json
+++ b/test/knownfailures.json
@@ -1062,6 +1062,7 @@
           "988-method-trace",
           "989-method-trace-throw",
           "993-breakpoints",
+          "1002-notify-startup",
           "1900-track-alloc",
           "1906-suspend-list-me-first",
           "1914-get-local-instance",