struct AStatus
This is a helper class that encapsulates a standard way to keep track of and chain binder errors
along with service specific errors.
It is not required to be used in order to parcel/receive transactions, but it is required in
order to be compatible with standard AIDL transactions since it is written as the header to the
out parcel for transactions which get executed (don't fail during unparceling of input arguments
or sooner).