android xml file invalid symbol: 'do', the xml file is from decompiled apk code

I know "do" is a reserved symbol in Java from this question Error in strings.xml: invalid symbol 'continue' so you cannot use it as a name for any object in your XML files or Java code.

But why decompiling a apk produces a invalid xml file? What could be the reason and how to solve the problem so I can rebuild the apk.