ProtocolV2ParserTest: Fix incorrect usage of ExpectedException

ProtocolV2ParserTest: Fix incorrect usage of ExpectedException

There should only be one statement after the expect(...) method.

Any additional statements after the statement that is expected to
throw will never be executed in a passing test. This can lead to
inappropriately passing tests where later incorrect assertions are
skipped by the thrown exception.

See https://errorprone.info/bugpattern/ExpectedExceptionChecker

Change-Id: I0d6350fafb281b6bdb04289f4cd5eb4bb159628b
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>