How to escape json-stylished String to work with MessageFormat?

I'm using java-17 and the following code snippet breaks because MessageFormat gets JSON symbols such as { and } and interprets them as its own formatters preventing the String to be formatted:

import java.math.BigDecimal;
import java.text.MessageFormat;

public class Test {

    public static void main(final String[] args) {
        System.out.println(MessageFormat.format("""
                {
                    "a": "{0}",
                 {
                  "b": "{0}"
                  "c": "{0}"
                  "d": {1,number,#.##}
                 }
                }""", "Test", new BigDecimal("10.123")));
    }
}

Here's the stack trace:

Exception in thread "main" java.lang.IllegalArgumentException: can't parse argument number: 
    "a": "{0}"
    at java.base/java.text.MessageFormat.makeFormat(MessageFormat.java:1454)
    at java.base/java.text.MessageFormat.applyPattern(MessageFormat.java:492)
    at java.base/java.text.MessageFormat.<init>(MessageFormat.java:371)
    at java.base/java.text.MessageFormat.format(MessageFormat.java:860)
    at Test.main(Test.java:9)
Caused by: java.lang.NumberFormatException: For input string: "
    "a": "{0}""
    at java.base/java.lang.NumberFormatException.forInputString(NumberFormatException.java:67)
    at java.base/java.lang.Integer.parseInt(Integer.java:654)
    at java.base/java.lang.Integer.parseInt(Integer.java:786)
    at java.base/java.text.MessageFormat.makeFormat(MessageFormat.java:1452)
    ... 4 more

What's the correct way to escape these symbols in order to MessageFormat actually formats the String?

Nothing should change in that syntax in Java 17 since the MessageFormat is known from Java 7. As cited here in the past: Accepted answer for Question #1187093

Within a String, a pair of single quotes can be used to quote any arbitrary characters except single quotes. For example, pattern string "'{0}'" represents string "{0}", not a FormatElement.