Instead of checking handshake done frame received, just check both endpoints' handshake state is HANDSHAKE_CONFIRMED. There is a possibility where HANDSHAKE_DONE frame is received before observer gets set. gfe-relnote: n/a (test only) PiperOrigin-RevId: 292396283 Change-Id: I36387fa17c292cbf69b68d8b532f4b1447014a6f