input: Write a python function to validate APRS_USER and APRS_PASSCODE are set correctly.
  assert validate_aprs_credentials("PythonEx", 1234) == True
  assert validate_aprs_credentials("", 1234) == False
  assert validate_aprs_credentials("PythonEx", 0) == False
output: def validate_aprs_credentials(APRS_USER, APRS_PASSCODE):
      if not APRS_USER or APRS_PASSCODE <= 0:
          return False
      return True