RFR: 8189441: Define algorithm names for keys derived from KeyAgreement [v2]

[Weijun Wang]

> Allow `Generic` as an algorithm in the `KeyAgreement::generateSecret(alg)` method.

Weijun Wang has updated the pull request incrementally with one additional commit since the last revision:

  add key size adjustment clarification

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Changes:
  - all: https://git.openjdk.org/jdk/pull/22650/files
  - new: https://git.openjdk.org/jdk/pull/22650/files/f7c03f78..3d62a503

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=22650&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=22650&range=00-01

  Stats: 8 lines in 2 files changed: 6 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/22650.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22650/head:pull/22650

PR: https://git.openjdk.org/jdk/pull/22650