Support OpenJDK 15+ for TLS (#960)
Support OpenJDK 15+ for TLS (#960)

OpenJDK 15+ appears to have a DelegatingSocketImpl that prevents getting
the FileDescriptor from a given Socket instance. If the returned
sockImpl is an instance of this, fetch the real sockImpl from the
"delegate" field.

google/conscrypt,google/conscrypt,google/conscrypt,google/conscrypt,google/conscrypt,google/conscrypt