libbinder: RPC avoid SIGPIPE

This was just being ignored before in our tests, but we can use
MSG_NOSIGNAL to avoid this.

Fixes: 183141167
Test: binderRpcTest on host and device (including after removing
RpcState::terminate which was avoiding SIGPIPE in at least some
cases)

Change-Id: I7c84fc28ff21400f2546f88403a79fae8985c4b7