8310923: Refactor Currency tests to use JUnit

[luchenlin]

I backport this for parity with 11.0.24-oracle.
Clean except some code lines are different, so make it clean.

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Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• JDK-8310923 needs maintainer approval

Issue

• JDK-8310923: Refactor Currency tests to use JUnit (Sub-task - P4)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk11u-dev.git pull/2625/head:pull/2625
$ git checkout pull/2625

Update a local copy of the PR:
$ git checkout pull/2625
$ git pull https://git.openjdk.org/jdk11u-dev.git pull/2625/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 2625

View PR using the GUI difftool:
$ git pr show -t 2625

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk11u-dev/pull/2625.diff

Webrev

Link to Webrev Comment

[bridgekeeper]

👋 Welcome back andrewlu! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

[openjdk]

❗ This change is not yet ready to be integrated.
See the Progress checklist in the description for automated requirements.

[openjdk]

This backport pull request has now been updated with issue from the original commit.

[mlbridge]

Webrevs

• 02: Full - Incremental (14c60deb)
• 01: Full - Incremental (50ac2bea)
• 00: Full (1335bfab)

[openjdk]

@luchenlin This backport pull request is now marked as clean

[openjdk]

⚠️ @luchenlin This change is now ready for you to apply for maintainer approval. This can be done directly in each associated issue or by using the /approval command.