libbinder: can't remark binder stability

Marking a binder should only ever happen by the AIDL compiler (where the
stability is tied to the build system and other API checks) or, for
existing hand-written binders, when they first leave the process.

In order to detect accidental mismarks of binders, it's a hard error.

Bug: 136027762
Test: binderStabilityTest
Change-Id: I8570300562b26c58da0ec872afbe130cac3d53bd