AndroidKeyStore and AndroidKeyPairGenerator tests

Adds tests for AndroidKeyStore and AndroidKeyPairGenerator in the
android.security package. Note that this test package is
android.keystore since the android.security package is taken by some
unrelated tests that tests platform security settings.

Bug: 8608597
Change-Id: I2d203bf6f685444dab06c84b173ade220ac7fc46
6 files changed