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/Android.bp b/test/Android.bp
index a11d5d9..a5d63c2 100644
--- a/test/Android.bp
+++ b/test/Android.bp
@@ -496,6 +496,7 @@
         "800-smali/jni.cc",
         "909-attach-agent/disallow_debugging.cc",
         "1001-app-image-regions/app_image_regions.cc",
+        "1002-notify-startup/startup_interface.cc",
         "1947-breakpoint-redefine-deopt/check_deopt.cc",
         "common/runtime_state.cc",
         "common/stack_inspect.cc",