Clean up ImageHeader section getters.

Test: m art-test-host-gtest
Test: testrunner.py --host
Change-Id: Iaea7ce6f9bc3ff3c6d9bb6fb598aa62333ebf30c
diff --git a/compiler/image_test.h b/compiler/image_test.h
index daa4b11..15f79cb 100644
--- a/compiler/image_test.h
+++ b/compiler/image_test.h
@@ -398,7 +398,7 @@
     ImageHeader image_header;
     ASSERT_EQ(file->ReadFully(&image_header, sizeof(image_header)), true);
     ASSERT_TRUE(image_header.IsValid());
-    const auto& bitmap_section = image_header.GetImageSection(ImageHeader::kSectionImageBitmap);
+    const auto& bitmap_section = image_header.GetImageBitmapSection();
     ASSERT_GE(bitmap_section.Offset(), sizeof(image_header));
     ASSERT_NE(0U, bitmap_section.Size());