Make JNI work correctly with default methods.

Also adds some tests for JNI and DefaultMethods.

Bug: 27259142
Bug: 24618811

(cherry picked from commit 3612149aee482ab7a17da68b0ef5fef3879729a2)

Change-Id: I31222e3e41059d803be1dbb0f40e1144ac4bf457
15 files changed