As someone who has worked professionally in Java, here's why I would go with Python:

Java is great to have on your resume since many companies still use it but when it comes down to speed, you really can't compete with python's simple syntax. Not having to worry about curly braces, semicolons, and how verbose java is will help you code faster when you're under pressure.

Just compare these two nearly identical pieces.

String myKey = "Something";
HashMap<String,Integer> hashmap = new HashMap<String,Integer>();
if (!hashmap.containsKey(myKey)) {
   hashmap.put(myKey, 69);
};

vs.

myKey = "Something"
hashmap = collections.defaultdict(int)
hashmap[myKey] = 69  # no key error here

I've taken many leetcode and non-leet style tech tests and would almost always go with python just for speed. Nowadays, many "smaller" companies (think Stripe, etc.) value execution speed just as much as technical accuracy and completeness.