Fix InsertDexFileInToClassLoader to handle null class loaders
am: f2bf9d6

* commit 'f2bf9d640e37b72be8b4f6016d4aa95a0e27b7b4':
  Fix InsertDexFileInToClassLoader to handle null class loaders

Change-Id: I9c0e4853e891c3d7de4c75303e717c0152104204