Refactor Choose/Confirm Lock flow to take user id

This is a first step to allow this flow to be reused for setting
a work profile-specific lock, to be used with the work challenge.

Change-Id: Iaa65fdab9021cda5f0a1d3bc526a6b54f8a7dd16

src/com/android/settings/ConfirmLockPassword.java

@@ -108,7 +108,9 @@ public class ConfirmLockPassword extends ConfirmDeviceCredentialBaseActivity {
         public void onCreate(Bundle savedInstanceState) {
             super.onCreate(savedInstanceState);
             mLockPatternUtils = new LockPatternUtils(getActivity());
-            mEffectiveUserId = Utils.getEffectiveUserId(getActivity());
+            Intent intent = getActivity().getIntent();
+            // Only take this argument into account if it belongs to the current profile.
+            mEffectiveUserId = Utils.getSameOwnerUserId(getActivity(), intent.getExtras());
         }
 
         @Override