Use SHA_2_256 for importWrappedKey

The spec requires that SHA1 not be allowed for wrapped keys and that
only SHA_2_256 be used. Unfortunately, the previous VTS required SHA1
support. This patch takes the middle ground by requiring SHA_2_256 be
supported for importWrappedKey, but not disallowing it from supporting
SHA1.

This makes it possible for a spec compliant keymaster to pass VTS
while not disqualifying shipped devices.

Bug: 129291873
Test: atest VtsHalKeymasterV4_0TargetTest:ImportWrappedKeyTest, Trusty
Change-Id: I6c3a9182b51f2e7a46173d5bfc34d3c3264d954f