RPC Binder: Fix TIPC disconnect error code

TIPC on Android returns ENOTCONN if the connection
goes down. Most of libbinder uses DEAD_OBJECT which is
-EPIPE instead. This adds a new function that converts
-ENOTCONN to DEAD_OBJECT manually when returning from
RpcTransportTipcAndroid, for better compatibility with
the rest of libbinder and its tests.

Bug: 230135749
Test: binderRpcToTrustyTest
Change-Id: I6e4b7bdbe214f23f195e14a0e023eba7e944085b