RFR: JDK-8329692 : Add more details to FrameStateTest.java test instructions

[Harshitha Onkar]

For the following manual test, more instructions are added as to what to expect for "hide,iconify and show" vs "hide,iconify,show and restore" for clarity.

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Commit messages:
 - minor update
 - added instructions for clarity

Changes: https://git.openjdk.org/jdk/pull/19008/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=19008&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8329692
  Stats: 15 lines in 1 file changed: 4 ins; 1 del; 10 mod
  Patch: https://git.openjdk.org/jdk/pull/19008.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/19008/head:pull/19008

PR: https://git.openjdk.org/jdk/pull/19008