Fix crash due to TextView.getText() returning null.

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
1 file changed