test(usb_serial_jtag): fix scenario

Author: urish

test/test_usb_serial_jtag.scenario.yaml

@@ -3,7 +3,8 @@ version: 1
 author: Uri Shaked
 
 steps:
-  - wait-serial: "Press ENTER to see the list of tests"
+  - wait-serial: "Press ENTER to see the list of tests."
+  - delay: 10ms # wait for the prompt to be ready
   - write-serial: "*\n"
   - wait-serial: "usb_serial_test: Oh, hello world 2, this test is for testing message and parse in python, time 298"
   - wait-serial: "usb_serial_test: Oh, hello world 1, this test is for testing message and parse in python, time 299"