RFR: 8349508: runtime/cds/appcds/TestParallelGCWithCDS.java should not check for specific output

[Calvin Cheung]

The `TestParallelGCWithCDS.java` test runs with small max heap and failed intermittently due to the expected output is missing. Instead of keep adding the expected output, the fix is just check that the JVM hasn't crashed. Also updating the `TestSerialGCWithCDS.java` test with similar fix.

Passed tier3 testing.

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Commit messages:
 - 8349508: runtime/cds/appcds/TestParallelGCWithCDS.java should not check for specific output

Changes: https://git.openjdk.org/jdk/pull/23485/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=23485&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8349508
  Stats: 15 lines in 2 files changed: 0 ins; 12 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/23485.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23485/head:pull/23485

PR: https://git.openjdk.org/jdk/pull/23485