Make test 1934 not flaky.

Test 1934 was slightly flaky since if the target thread is stopped
during a class-load you would get a ExceptionInInitializerError
(or a DCHECK failure) instead of the expected error. This change
removes the DCHECK if we are using AsyncExceptions and force the class
to be initialized before running the test.

Test: ./test.py --host -j50
Bug: 74446036

Change-Id: I164611f08c7a6ba4ea127cda6cf1df3dca25f08d