Cannot use logging.level to set levels for loggers in inner classes

[garyrussell]

See spring-projects/spring-kafka#714

$ is stripped out by ConfigurationPropertyName.adapt().

	/**
	 * Create a {@link ConfigurationPropertyName} by adapting the given source. The name
	 * is split into elements around the given {@code separator}. This method is more
	 * lenient than {@link #of} in that it allows mixed case names and '{@code _}'
	 * characters. Other invalid characters are stripped out during parsing.
	 * <p>
	 * The {@code elementValueProcessor} function may be used if additional processing is
	 * required on the extracted element values.
	 * @param name the name to parse
	 * @param separator the separator used to split the name
	 * @param elementValueProcessor a function to process element values
	 * @return a {@link ConfigurationPropertyName}
	 */
	static ConfigurationPropertyName adapt(CharSequence name, char separator,
			Function<CharSequence, CharSequence> elementValueProcessor) {

[garyrussell]

After reading the javadocs, I found that this works...

logging.level.[org.springframework.kafka.listener.KafkaMessageListenerContainer$ListenerConsumer]=info

...although STS doesn't approve of the syntax.

[mbhave]

This limitation is being tracked in #13404. There is another issue to document the current behavior - #13506