Improve QuicSpdyStreamTest to call OnCryptoHandshakeEvent on the session to ensure that the various HTTP/3 initialization steps happen, matching what happens in production. gfe-relnote: n/a - test only PiperOrigin-RevId: 274254994 Change-Id: Ic9053ad49c905e4aa37a41691e7f6e2c31d6c53c