libbinder: test parcel allocted on another thread

This shouldn't ordinarily be done, but it does in Java, and it may be
done in the future if we cache Parcel objects in the NDK/Rust backends.
So, using the API which we test in Java there to fix the problem.

Bug: 139327211
Test: atest binderLibTest
Change-Id: Ia60ebb91bf70d30f7183ce55ae4f0c6e8e0a7a24