Update KeyPairGeneratorTest for EC keys

EC keys can have two different formats: explicit parameters or named
curve. When you generate a key, it's typically a named curve. When you
write out the parameters of the named curve and read them back, it's no
longer named.

Change the comparison to match the EC parameters themselves instead of
concerning the test with named curve stuff.

Change-Id: I4fc2fe38cf497b2ce96d1258c54833c717152ad2