AutoSize TextView - API polish - no RuntimeException in signature

Do not mention RuntimeException subclasses in throws clauses in
method signatures.

Bug: 37514926
Test: cts-tradefed run cts-dev -m CtsWidgetTestCases -t \
      android.widget.cts.TextViewTest

Change-Id: Ia5bf4cd64e12c53dd7c409b6e44efec4983ae62e