RESTRICT AUTOMERGE Close TextClassifier native resources.

Bug: 122904322
Test: atest android.view.textclassifier.TextClassificationManagerTest
Test: (MANUAL)
      1. Start an app with a TextView
      2. Select the text to trigger the text selection toolbar and TextClassifier
      3. Close the app's activity by repeatedly clicking back on the nav bar
      4. Start a Profiler for the app and observe for memory growth
      5. Repeat 1 - 3 several times and observe.
         If the bug still exists, memory should grow at about 4 - 5MB.
	 If the bug is fixed, Memory should remain about the same across activity restarts.

Change-Id: Id9a60dea85cf3949de030042537287ddb29842a2