Fix ECDSA upcalls from TLS/SSL into JCA.

When BoringSSL/OpenSSL TLS/SSL stack operates on opaque private keys
(those that don't expose their key material) it upcalls (via
Conscrypt's NativeCrypto) into corresponding JCA Signature and Cipher

This fixes a crash in the ECDSA upcall when Conscrypt is used with

Bug: 21738458
Change-Id: I51645bd93f965fe7fcabe45e87276d533513b378
1 file changed