Always swallow the IllegalStateException from AsyncTask.

Because we use suppliers for TextClassifier, the
mTextClassificationHelper::isTextClassifierDestroyed actually always
returns false. Always swallows the exception temporarily to unblock
other teams. We may want to keep a reference of the TCSession in the
AsyncTask and check it ideally (b/174300371).

Bug: 174300371
Fix: 172627102
Test: atest AccessibilityTextTraversalTest.java
Change-Id: I5988db992956d666e24e608cd99d4fc87fd6820b