Prevent fragment rotation crashes.

Also, causes right fragment to retain after rotation and recreation.

Bug: 25154818
Bug: 24910704
Change-Id: Icafbc7ba6f3ad877c2d28d92e510b9afbd822b65
diff --git a/src/com/android/dialer/filterednumber/ManageBlockedNumbersActivity.java b/src/com/android/dialer/filterednumber/ManageBlockedNumbersActivity.java
index 581ff98..f785cf7 100644
--- a/src/com/android/dialer/filterednumber/ManageBlockedNumbersActivity.java
+++ b/src/com/android/dialer/filterednumber/ManageBlockedNumbersActivity.java
@@ -49,7 +49,10 @@
         super.onCreate(savedInstanceState);
         setContentView(R.layout.blocked_numbers_activity);
 
-        showManagementUi();
+        // If savedInstanceState != null, the Activity will automatically restore the last fragment.
+        if (savedInstanceState == null) {
+            showManagementUi();
+        }
     }
 
     public void showManagementUi() {