Remove Ljava/lang/Object; from inference fall back types
Remove Ljava/lang/Object; from inference fall back types

Summary: With the recent changes we made to DexTypeDomain and the type checker, we shouldn't consider j.l.Object as a fall back type. We should enforce type safety check on values with an inferred type as j.l.Object.

Reviewed By: yuxuanchen1997

Differential Revision: D20811391

fbshipit-source-id: 5a4522dec87c6da662d5616dd300396a235685d3

facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex