binder_rs: Add sized_read to Parcel

Add a new Parcel::sized_read method that builds
a sized readable sub-parcel with an end position and is
used by the AIDL compiler to deserialize parcelables.

Bug: 186724059
Test: atest aidl_integration_test
Change-Id: Iba064858fe8b434e89732d437ccc304bc6cd172a