LockPatternUtils clean up continued

- Deprecate Settings.Secure.LOCK_PATTERN_ENABLED
- Remove unused permanent lock out
- Disallow empty/null arguments to saveLockPattern and saveLockPassword
- Refactor repeated quality checks

Change-Id: I6f369eb60f8f6bb1e33384cd06534c713ab52e79
diff --git a/core/java/android/provider/Settings.java b/core/java/android/provider/Settings.java
index c1e0bd2..687db7c 100644
--- a/core/java/android/provider/Settings.java
+++ b/core/java/android/provider/Settings.java
@@ -3669,7 +3669,11 @@
 
         /**
          * Whether autolock is enabled (0 = false, 1 = true)
+         *
+         * @deprecated Use {@link android.app.KeyguardManager} to determine the state and security
+         *             level of the keyguard.
          */
+        @Deprecated
         public static final String LOCK_PATTERN_ENABLED = "lock_pattern_autolock";
 
         /**