Add a lock to guard TCSession's destroy behavior.

Bug: 158249027
Test: atest TextClassifierServiceTest
Test: atest CtsTextClassifierTestCases
Test: atest core/tests/coretests/src/android/view/textclassifier

Change-Id: Iab8658a0919bd59664c7644ff8e6f53f866e7404
1 file changed