Revert "Revert "Make synthetic password enabled by default""

This reverts commit 4519c0b1ef6ee00430f4c223aba1803fa862c031.

Change-Id: Ie39f1f5af085598fd9b919f25fd6548b0786524c
diff --git a/services/core/java/com/android/server/locksettings/LockSettingsShellCommand.java b/services/core/java/com/android/server/locksettings/LockSettingsShellCommand.java
index d1fb28a..d730c56 100644
--- a/services/core/java/com/android/server/locksettings/LockSettingsShellCommand.java
+++ b/services/core/java/com/android/server/locksettings/LockSettingsShellCommand.java
@@ -71,7 +71,7 @@
                     runClear();
                     break;
                 case COMMAND_SP:
-                    runEnableSp();
+                    runChangeSp();
                     break;
                 case COMMAND_SET_DISABLED:
                     runSetDisabled();
@@ -107,10 +107,15 @@
         mNew = getNextArg();
     }
 
-    private void runEnableSp() {
-        if (mNew != null) {
-            mLockPatternUtils.enableSyntheticPassword();
-            getOutPrintWriter().println("Synthetic password enabled");
+    private void runChangeSp() {
+        if (mNew != null ) {
+            if ("1".equals(mNew)) {
+                mLockPatternUtils.enableSyntheticPassword();
+                getOutPrintWriter().println("Synthetic password enabled");
+            } else if ("0".equals(mNew)) {
+                mLockPatternUtils.disableSyntheticPassword();
+                getOutPrintWriter().println("Synthetic password disabled");
+            }
         }
         getOutPrintWriter().println(String.format("SP Enabled = %b",
                 mLockPatternUtils.isSyntheticPasswordEnabled()));