Handle TransactionTooLargeException in ServicePermsTest

SELinux policies prevent some binder transactions from succeeding on dump calls
resulting in a TransactionTooLargeException being thrown. Catch this exception
in the context of the test and assume that it is the result of an SELinux
denial, and thus that no data is leaked.

Bug: 13675745
Change-Id: I249c51c760129f6981ec47cc88cf28e367784b51