Clarify that `ParameterizedType.getOwnerType()` always return `null` in a few scenarios.
------------- Commit messages: - 8306039: ParameterizedType.getOwnerType() documentation is incomplete about null result Changes: https://git.openjdk.org/jdk/pull/19977/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=19977&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8306039 Stats: 22 lines in 3 files changed: 2 ins; 8 del; 12 mod Patch: https://git.openjdk.org/jdk/pull/19977.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/19977/head:pull/19977 PR: https://git.openjdk.org/jdk/pull/19977
