Implement the clone trait for ParcelableHolder

For the parity with the C++/NDK implementation, make the Rust
ParcelableHolder cloneable.

Bug: 210093811
Fix: 285042738
Test: m
Test: declare a cloneable Parcelable with a ParcelableHolder and then
check if build succeeds
Change-Id: Iac161ec01007045cf1bee0632e56494e76f9c04a
1 file changed