Further Credentials-related clean-up

Remove methods from the Credentials class that are no longer used,
now that KeyChain no longer depends on the presence of a screen lock.

Bug: 120901345
Test: That it builds, manually with CtsVerifier
Change-Id: I37ad617f076a9ea9b5a5c789cd1da77110ad7b3b
diff --git a/keystore/java/android/security/Credentials.java b/keystore/java/android/security/Credentials.java
index 072fe73..2ae28f5 100644
--- a/keystore/java/android/security/Credentials.java
+++ b/keystore/java/android/security/Credentials.java
@@ -16,12 +16,6 @@
 
 package android.security;
 
-import android.annotation.UnsupportedAppUsage;
-import android.content.ActivityNotFoundException;
-import android.content.Context;
-import android.content.Intent;
-import android.util.Log;
-
 import com.android.org.bouncycastle.util.io.pem.PemObject;
 import com.android.org.bouncycastle.util.io.pem.PemReader;
 import com.android.org.bouncycastle.util.io.pem.PemWriter;
@@ -34,7 +28,6 @@
 import java.io.Reader;
 import java.io.Writer;
 import java.nio.charset.StandardCharsets;
-import java.security.KeyPair;
 import java.security.cert.Certificate;
 import java.security.cert.CertificateEncodingException;
 import java.security.cert.CertificateException;
@@ -53,8 +46,6 @@
 
     public static final String INSTALL_AS_USER_ACTION = "android.credentials.INSTALL_AS_USER";
 
-    public static final String UNLOCK_ACTION = "com.android.credentials.UNLOCK";
-
     /** Key prefix for CA certificates. */
     public static final String CA_CERTIFICATE = "CACERT_";
 
@@ -171,58 +162,6 @@
         }
     }
 
-    private static Credentials singleton;
-
-    @UnsupportedAppUsage
-    public static Credentials getInstance() {
-        if (singleton == null) {
-            singleton = new Credentials();
-        }
-        return singleton;
-    }
-
-    @UnsupportedAppUsage
-    public void unlock(Context context) {
-        try {
-            Intent intent = new Intent(UNLOCK_ACTION);
-            context.startActivity(intent);
-        } catch (ActivityNotFoundException e) {
-            Log.w(LOGTAG, e.toString());
-        }
-    }
-
-    public void install(Context context) {
-        try {
-            Intent intent = KeyChain.createInstallIntent();
-            context.startActivity(intent);
-        } catch (ActivityNotFoundException e) {
-            Log.w(LOGTAG, e.toString());
-        }
-    }
-
-    @UnsupportedAppUsage
-    public void install(Context context, KeyPair pair) {
-        try {
-            Intent intent = KeyChain.createInstallIntent();
-            intent.putExtra(EXTRA_PRIVATE_KEY, pair.getPrivate().getEncoded());
-            intent.putExtra(EXTRA_PUBLIC_KEY, pair.getPublic().getEncoded());
-            context.startActivity(intent);
-        } catch (ActivityNotFoundException e) {
-            Log.w(LOGTAG, e.toString());
-        }
-    }
-
-    @UnsupportedAppUsage
-    public void install(Context context, String type, byte[] value) {
-        try {
-            Intent intent = KeyChain.createInstallIntent();
-            intent.putExtra(type, value);
-            context.startActivity(intent);
-        } catch (ActivityNotFoundException e) {
-            Log.w(LOGTAG, e.toString());
-        }
-    }
-
     /**
      * Delete all types (private key, user certificate, CA certificate) for a
      * particular {@code alias}. All three can exist for any given alias.