RFR: 8372307: Clean up the leftover code comment references to file.encoding in java_props_md.c

[Naoto Sato]

On Fri, 29 Aug 2025 14:25:25 GMT, Igor Rudenko <duke at openjdk.org> wrote:

> The `file.encoding` system property is no longer used by the JDK.
> Updated code comments to reference the correct replacement: `native.encoding`.

The change looks good. However, the description in the PR text:

The file.encoding system property is no longer used by the JDK.

is not correct. `file.encoding` system property is still used. Please correct it.

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

Marked as reviewed by naoto (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/27004#pullrequestreview-3494130431