Implement the ECKeyPairGenerator initialize func

Aim to solve openj9 issue 18320.

DefaultSignatureAlgorithm test was run in
those Redhat OS based machines in a non-FIPS
mode. But a FIPS version of openssl was used
in those machines. 192-bit size of EC key is
not allowed by a FIPS version of openssl. The
code path went to a replacement EC key-pair
generator Java implementation.

Removed 192-bits test to alias with other
JDK versions.

test/jdk/sun/security/tools/keytool/fakegen/DefaultSignatureAlgorithm.java

@@ -60,7 +60,6 @@ public static void main(String[] args) throws Exception {
         check("DSA", 1024, null, "SHA256withDSA");
         check("DSA", 3072, null, "SHA256withDSA");
 
-        check("EC", 192, null, "SHA256withECDSA");
         check("EC", 384, null, "SHA384withECDSA");
         check("EC", 571, null, "SHA512withECDSA");