RFR: 8268544: some runtime/sealedClasses tests should be run in driver mode

[Igor Ignatyev]

Hi all,

could you please review this small and trivial patch that changes the execution mode to `driver` in two `runtime/sealedClasses` tests?

testing:  `runtime/sealedClasses` on `{linux,windows,macosx}-x64`

Thanks,
-- Igor

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Commit messages:
 - 8268544

Changes: https://git.openjdk.java.net/jdk/pull/4463/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=4463&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8268544
  Stats: 6 lines in 2 files changed: 2 ins; 0 del; 4 mod
  Patch: https://git.openjdk.java.net/jdk/pull/4463.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/4463/head:pull/4463

PR: https://git.openjdk.java.net/jdk/pull/4463