Stop showing dialog when the Activity is already gone

Actually showDialog() is deprecated method and this whole
Activity should be rewritten using DialogFragment. This is
just for preventing unnecessary crash during automated testing

Bug: 5166487
Change-Id: I94fcabf1b916d86cdc9333f337b43dafacae4f72
diff --git a/src/com/android/contacts/vcard/ImportVCardActivity.java b/src/com/android/contacts/vcard/ImportVCardActivity.java
index 2baa9cb..054e018 100644
--- a/src/com/android/contacts/vcard/ImportVCardActivity.java
+++ b/src/com/android/contacts/vcard/ImportVCardActivity.java
@@ -170,7 +170,9 @@
         }
         @Override
         public void run() {
-            showDialog(mResId);
+            if (!isFinishing()) {
+                showDialog(mResId);
+            }
         }
     }