java.lang: fix escaped characters

Both \s and \uuu0041 are valid character escapes in Java.

See
https://docs.oracle.com/javase/specs/jls/se17/html/jls-3.html#jls-3.3 and
https://docs.oracle.com/javase/specs/jls/se17/html/jls-3.html#jls-3.10.7