Disable KM4 HMAC key agreement

StrongBox doesn't yet have key agreement implemented, which breaks
keystore if TEE KM is upgraded to KM4.  This disables it temporarily.

Bug: 77533310
Test: Boot and verify that keystore is running correctly.
Change-Id: I8505f634735d1efc5a196fdfd0910b1b26da7547
1 file changed