Revert "MediaDrm#mNativeContext is a long, not int."

This reverts commit 097f939898c38ca7503b68425dc357f5632c5c3e.

Change-Id: Ib429ae05a67bbb93559d104dfe50963c39a1f180
Merge "Revert "MediaDrm#mNativeContext is a long, not int."" into kk4.4-caf