Fix crash in when restoring CredentialCheckResultTracker Fragment

Bug: 23956504
Change-Id: I884e47a793d6bc00cc0c54fe9e3d4bcf4e0199c1
diff --git a/src/com/android/settings/CredentialCheckResultTracker.java b/src/com/android/settings/CredentialCheckResultTracker.java
index 7f72caa..5c55073 100644
--- a/src/com/android/settings/CredentialCheckResultTracker.java
+++ b/src/com/android/settings/CredentialCheckResultTracker.java
@@ -23,7 +23,7 @@
 /**
  * An invisible retained fragment to track lock check result.
  */
-class CredentialCheckResultTracker extends Fragment {
+public class CredentialCheckResultTracker extends Fragment {
 
     private Listener mListener;
     private boolean mHasResult = false;