e4e1958b65
The charset "default" is an alias for US-ASCII, not the JVM's default
charset. This commit updates the built-in Logback configuration to
use Charset.defaultCharset().name() in place of "default" in the
Java-based configuration. In the XML-based configuration where
Charset.defaultCharset().name() cannot be called, we emulate its
behaviour [1] by using the file.encoding system property, falling back
to UTF-8 when it's not set.
Fixes gh-27230
[1] 19be6113dd/jdk/src/share/classes/java/nio/charset/Charset.java (L604-L617)