RFR: 8357149: Test runtime/cds/appcds/aotCode/AOTCodeFlags.java is broken after JDK-8354887

[Calvin Cheung]

Simple test fix to ensure the `-XX:+UnlockDiagnosticVMOptions` flag is specified before a diagnostic flag such as `-XX:+AOTAdapterCaching`.

Tested with the following JDK builds on linux-x64:
OpenJDK non-debug, OpenJDK debug, Oracle JDK non-debug, Oracle JDK debug.

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Commit messages:
 - 8351749: Test runtime/cds/appcds/aotCode/AOTCodeFlags.java is broken after JDK-8354887

Changes: https://git.openjdk.org/jdk/pull/25275/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=25275&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8357149
  Stats: 3 lines in 1 file changed: 1 ins; 1 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/25275.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25275/head:pull/25275

PR: https://git.openjdk.org/jdk/pull/25275