faft: Add delay for keypresses in firmware screen

BUG=chromium-os:34392
TEST=Run FAFT suite and check switching keyboard dev mode works.

Change-Id: Ie005606b7480ce944902105460c81e45cf8ab733
Signed-off-by: Vic Yang <victoryang@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/37000
Reviewed-by: Tom Wai-Hong Tam <waihong@chromium.org>
diff --git a/server/cros/faftsequence.py b/server/cros/faftsequence.py
index 90a9c1b..adde4e9 100644
--- a/server/cros/faftsequence.py
+++ b/server/cros/faftsequence.py
@@ -861,7 +861,7 @@
             self.press_ctrl_d()
         else:
             self.press_enter()
-        time.sleep(self.delay.firmware_screen)
+        time.sleep(self.delay.confirm_screen)
         self.press_enter()