Fix issued with non-public interface methods.

Some APK's ship with dex files containing non-public interface
methods. These would cause crashes on newer versions of ART due to
stricter verification of dex files. Make ART emit a warning but allow
this behavior.

Bug: 27928832

Change-Id: Ia3689ee091aa154fb5954b1f6dd50c489128acce
diff --git a/runtime/class_linker.cc b/runtime/class_linker.cc
index 7060593..f4880e0 100644
--- a/runtime/class_linker.cc
+++ b/runtime/class_linker.cc
@@ -5874,9 +5874,14 @@
           !target_name_comparator.HasSameNameAndSignature(
               current_method->GetInterfaceMethodIfProxy(image_pointer_size_))) {
         continue;
+      } else if (!current_method->IsPublic()) {
+        // The verifier should have caught the non-public method for dex version 37. Just warn and
+        // skip it since this is from before default-methods so we don't really need to care that it
+        // has code.
+        LOG(WARNING) << "Interface method " << PrettyMethod(current_method) << " is not public! "
+                     << "This will be a fatal error in subsequent versions of android. "
+                     << "Continuing anyway.";
       }
-      // The verifier should have caught the non-public method.
-      DCHECK(current_method->IsPublic()) << "Interface method is not public!";
       if (UNLIKELY(chosen_iface.Get() != nullptr)) {
         // We have multiple default impls of the same method. This is a potential default conflict.
         // We need to check if this possibly conflicting method is either a superclass of the chosen