Create Work Challenge per-user condition

Change the current static condition to a per-user condition so we
can check and enable/disable the work challenge properly. Also add
an isAllowed API, as the Work Challenge can only be used when the
user's DPC targets N or above to maintain backwards compatibility.

Change-Id: I0cb8b475838816801868ffb24726407aa257b4de
diff --git a/services/core/java/com/android/server/pm/UserManagerService.java b/services/core/java/com/android/server/pm/UserManagerService.java
index 3d614a3..ce6b369 100644
--- a/services/core/java/com/android/server/pm/UserManagerService.java
+++ b/services/core/java/com/android/server/pm/UserManagerService.java
@@ -276,6 +276,8 @@
     private final ArrayList<UserRestrictionsListener> mUserRestrictionsListeners =
             new ArrayList<>();
 
+    private final LockPatternUtils mLockPatternUtils;
+
     private static UserManagerService sInstance;
 
     public static UserManagerService getInstance() {
@@ -320,6 +322,7 @@
         }
         mLocalService = new LocalService();
         LocalServices.addService(UserManagerInternal.class, mLocalService);
+        mLockPatternUtils = new LockPatternUtils(mContext);
     }
 
     void systemReady() {
@@ -456,7 +459,7 @@
     @Override
     public int getCredentialOwnerProfile(int userHandle) {
         checkManageUsersPermission("get the credential owner");
-        if (!LockPatternUtils.isSeparateWorkChallengeEnabled()) {
+        if (!mLockPatternUtils.isSeparateProfileChallengeEnabled(userHandle)) {
             synchronized (mUsersLock) {
                 UserInfo profileParent = getProfileParentLU(userHandle);
                 if (profileParent != null) {