Remove the duplicate() method from KeyStore. It is backed by dead code in the Keystore service, which (as far as I can tell) is not doing the right thing. Previous conversations with Keystore team members suggested this API should not be used and it is marked for removal in the Keystore service. Bug: 72037261 Test: That it compiles. Change-Id: I7f8af95473c876340cbd5c73dd88c5d0282897b3