[DO NOT MERGE] keymaster: add an EC attestation test

Add a test that creates an EC key by
using key-bits (rather than curve-id),
and check that the attestation message
corresponds to key characteristics.

Bug: 122375834
Bug: 119542230
Test: VTS passes
Change-Id: Iad6ff2ca90a951124940943f2484f9fb9f813a19
1 file changed