Hide "Configure input method" button when the screen is locked.

Bug: 5022109

Change-Id: I5c6b59044d03b3f0335de1f602d1c3749b038c75
diff --git a/services/java/com/android/server/InputMethodManagerService.java b/services/java/com/android/server/InputMethodManagerService.java
index 18d393f..93ece70 100644
--- a/services/java/com/android/server/InputMethodManagerService.java
+++ b/services/java/com/android/server/InputMethodManagerService.java
@@ -35,6 +35,7 @@
 
 import android.app.ActivityManagerNative;
 import android.app.AlertDialog;
+import android.app.KeyguardManager;
 import android.app.Notification;
 import android.app.NotificationManager;
 import android.app.PendingIntent;
@@ -160,6 +161,7 @@
 
     // Ongoing notification
     private final NotificationManager mNotificationManager;
+    private final KeyguardManager mKeyguardManager;
     private final Notification mImeSwitcherNotification;
     private final PendingIntent mImeSwitchPendingIntent;
     private final boolean mShowOngoingImeSwitcherForPhones;
@@ -520,6 +522,8 @@
             }
         });
 
+        mKeyguardManager = (KeyguardManager)
+                mContext.getSystemService(Context.KEYGUARD_SERVICE);
         mNotificationManager = (NotificationManager)
                 mContext.getSystemService(Context.NOTIFICATION_SERVICE);
         mImeSwitcherNotification = new Notification();
@@ -2118,7 +2122,8 @@
                         }
                     });
 
-            if (showSubtypes) {
+            if (showSubtypes && !(mKeyguardManager.isKeyguardLocked()
+                    && mKeyguardManager.isKeyguardSecure())) {
                 mDialogBuilder.setPositiveButton(
                         com.android.internal.R.string.configure_input_methods,
                         new DialogInterface.OnClickListener() {