This enforces the randomized encryption requirement (IND-CPA), if
requested, when generating asymmetric key pairs. Whether randomized
encryption is used depends on the encryption padding modes authorized
for the key pair. Thus, if randomized encryption is required, the
KeyPairGenerator must reject attempts to generate keys authorized for
encryption using non-compliant padding schemes.
This is similar to the existing check in AndroidKeyStoreImpl during
asymmetric key import.
Bug: 22179911
Change-Id: I3d85367259c17bd44198a736ace853d0d3567d5e
fdbc02a433