Foreach can not manipulate a String list?

I found this thread on the topic and I wondered why it's so hard in Java to replace a value in a List.

My code looks ugly like this:

    List<String> stringList = new ArrayList<>();
    // ... add some elements
    for (int i = 0; i< stringList.size(); ++i) {
        if (stringList.get(i).contains("%")) {
            stringList.set(i, stringList.get(i).replace("%", backupStorePath));
        }
    }

Is this really the only way to do this? Why can't I use a foreach loop?

for (String command : stringList) {
    command = command.replace("%", backupStorePath);
}

This must be a java's "Copy by value" problem and String being immutable, but why was it implemented like that? Why is command a copy of the original reference and not the original itself?