RFR: 8342183: Update tests to use stronger algorithms and keys [v4]

[Fernando Guallini]

> Several tests are identified to use weak/legacy algorithms. As these tests purpose is not to exercise weak algorithms, these are updated in this PR to use stronger algorithms. If the test uses a weak key, it is updated as well.

Fernando Guallini has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 16 commits:

 - Merge branch 'master' into 8342183
 - based on comments
 - Merge branch 'master' into 8342183
 - add more algos to TestExplicitKeyLength.java
 - Merge branch 'master' into 8342183
 - added changes in SecurityUtils.java and security/DiffieHellmanGroup.java
 - refactor SupportedDHParamGens.java
 - fixed SupportedDHParamGensLongKey.java
 - Updated keysizes to use SecurityUtils in KeyToolTest
 - Updated keysizes to use SecurityUtils
 - ... and 6 more: https://git.openjdk.org/jdk/compare/751a914b...081b7cd1

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Changes: https://git.openjdk.org/jdk/pull/21578/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21578&range=03
  Stats: 268 lines in 35 files changed: 142 ins; 9 del; 117 mod
  Patch: https://git.openjdk.org/jdk/pull/21578.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21578/head:pull/21578

PR: https://git.openjdk.org/jdk/pull/21578