ANDROID: rust_binder: adjust errors from death notifications

Rust Binder currently returns an error when death notifications are
registered or removed illegally. This causes tests that use the kernel
interface incorrectly to fail. To have the same behavior as C Binder,
adjust the death notification logic to print but otherwise ignore these
error conditions.

Bug: 430659969
Change-Id: Ia11aebea74ae1441fc48e40cbf43fae56bf3be54
Signed-off-by: Alice Ryhl <aliceryhl@google.com>