Extract SshKeyInfo from GetSshKeys to extension API

Change-Id: I900a527a5b0d1d2635f54e200fdb5a2f32c0596d

gerrit-extension-api/src/main/java/com/google/gerrit/extensions/common/SshKeyInfo.java

@@ -0,0 +1,24 @@
+// Copyright (C) 2016 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.extensions.common;
+
+public class SshKeyInfo {
+  public Integer seq;
+  public String sshPublicKey;
+  public String encodedKey;
+  public String algorithm;
+  public String comment;
+  public Boolean valid;
+}