ART: Add trace around app image verification

To track verification times in debug builds.

Bug: 35644369
Test: m test-art-host
Change-Id: I131a713464e2bd44125e5091e9c20cec600a87e0
diff --git a/runtime/class_linker.cc b/runtime/class_linker.cc
index d3eb29b..cd7a94e 100644
--- a/runtime/class_linker.cc
+++ b/runtime/class_linker.cc
@@ -1819,6 +1819,7 @@
   if (kIsDebugBuild && app_image) {
     // This verification needs to happen after the classes have been added to the class loader.
     // Since it ensures classes are in the class table.
+    ScopedTrace trace("VerifyAppImage");
     VerifyAppImage(header, class_loader, dex_caches, class_table, space);
   }