TC: Fix null PendingIntent being passed to RemoteAction

Problem was RemoteAction(...) takes a non-null PendingIntent but
TextClassification.createPendingIntent(...) returns a nullable PendingIntent.

Bug: 78515224
Test: manual
  - Disable Contacts apps in settings
  - Select a phone number in a TextView
  - Verify that a Phone smart action is displayed
Test: bit FrameworksCoreTests:android.view.textclassifier.TextClassificationManagerTest
Test: bit CtsViewTestCases:android.view.textclassifier.cts.TextClassificationManagerTest
Change-Id: Icab581d4eef38b4801d1b9ee3af04ffefd1eec6f