RFR: 8355241: Move NativeDialogToFrontBackTest.java PL test to manual category

[Abhishek Kumar]

`NativeDialogToFrontBackTest.java` test was moved to open PL file while converting from applet and open sourcing in [this PR](https://github.com/openjdk/jdk/pull/24685). It should be under Client manual tests category in PL file.

Moved the PL test to manual category

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Commit messages:
 - Move PL test to manual category

Changes: https://git.openjdk.org/jdk/pull/24790/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=24790&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8355241
  Stats: 2 lines in 1 file changed: 1 ins; 1 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/24790.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24790/head:pull/24790

PR: https://git.openjdk.org/jdk/pull/24790