RFR: 8374317: Change GCM IV size to 12 bytes when encrypting/decrypting TLS session ticket

[Artur Barashev]

12 bytes is the recommended size for GCM per NIST SP 800-38D:

For IVs, it is recommended that implementations restrict support to the length of 96 bits, to
promote interoperability, efficiency, and simplicity of design.`

Larger IV size requires an extra hashing step (GHASH). Currently we have it set to 16 bytes.

-------------

Commit messages:
 - 8374317: Change GCM IV size to 12 bytes when encrypting/decrypting TLS session ticket

Changes: https://git.openjdk.org/jdk/pull/28971/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=28971&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8374317
  Stats: 3 lines in 1 file changed: 1 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/28971.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/28971/head:pull/28971

PR: https://git.openjdk.org/jdk/pull/28971