RESTRICT AUTOMERGE Do not linkify text with RLO/LRO characters.

Also don't show smart actions for selections in text with unsupported
characters.

Bug: 116321860
Test: runtest -x cts/tests/tests/text/src/android/text/util/cts/LinkifyTest.java

Change-Id: Id271cab8aef6b9b13ef17f1a8654c7616f75cf13
(cherry picked from commit 73f398d3)