This CL ensures that a null text is not passed to
TextClassificationHelper.reset(...)
This CL does not handle the issue of TextView.getText() being null.
Bug: 65682674
Test: none
Merged-In: Id8bdc062ecf21cc14810586580fef9052672cfd8
Change-Id: Id8bdc062ecf21cc14810586580fef9052672cfd8