Clean up ImageHeader section getters.

Test: m art-test-host-gtest
Test: testrunner.py --host
Change-Id: Iaea7ce6f9bc3ff3c6d9bb6fb598aa62333ebf30c
diff --git a/runtime/intern_table.cc b/runtime/intern_table.cc
index f4da5a4..5b93d3b 100644
--- a/runtime/intern_table.cc
+++ b/runtime/intern_table.cc
@@ -182,7 +182,7 @@
   for (gc::space::ImageSpace* image_space : image_spaces) {
     const ImageHeader* const header = &image_space->GetImageHeader();
     // Check if we have the interned strings section.
-    const ImageSection& section = header->GetImageSection(ImageHeader::kSectionInternedStrings);
+    const ImageSection& section = header->GetInternedStringsSection();
     if (section.Size() > 0) {
       AddTableFromMemoryLocked(image_space->Begin() + section.Offset());
     }