Merge "libbinder: remove unused context variables" am: 280af8eb16 am: 3219ae64bc am: 65e60df3d2 am: a4fb71cc9d am: eb1e778ed2

Original change: https://android-review.googlesource.com/c/platform/frameworks/native/+/1416688

Change-Id: I2ee9d93db05abefa02e0961d11d04caa56c2aafa