RFR: 8313621: test/jdk/jdk/internal/math/FloatingDecimal/TestFloatingDecimal should use RandomFactory [v3]

[Brian Burkhalter]

> Change test to use `RandomFactory` instead of `new Random()` and convert it to JUnit 5.

Brian Burkhalter has updated the pull request incrementally with one additional commit since the last revision:

  8313621: Initialize NUM_RANDOM_TESTS more clearly

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Changes:
  - all: https://git.openjdk.org/jdk/pull/16130/files
  - new: https://git.openjdk.org/jdk/pull/16130/files/3f4fc63d..b6e22fca

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=16130&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=16130&range=01-02

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/16130.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/16130/head:pull/16130

PR: https://git.openjdk.org/jdk/pull/16130