Update to INFO to not confuse adb logcat readers.

With the move to JIT, we can get such warnings as we may not
have an oat file and ART does not have the rights to create it.

We're working on a cleaner solution that will avoid emitting the
message.

bug:26217329

Change-Id: If4418274d0fb9bd9f79f5b504b82c197228a34a7
diff --git a/runtime/oat_file_manager.cc b/runtime/oat_file_manager.cc
index ea6d3ff..5cb1858 100644
--- a/runtime/oat_file_manager.cc
+++ b/runtime/oat_file_manager.cc
@@ -301,7 +301,7 @@
   // Update the oat file on disk if we can. This may fail, but that's okay.
   // Best effort is all that matters here.
   if (!oat_file_assistant.MakeUpToDate(/*out*/&error_msg)) {
-    LOG(WARNING) << error_msg;
+    LOG(INFO) << error_msg;
   }
 
   // Get the oat file on disk.