faft: Migrate tests to python 3.

Add PY_VERSION = 3 to control files for tests that don't
require changes to be compatible with python 2 and 3.

BUG=b:197023900
TEST=firmware_*

Change-Id: Idd424e83793764952983e449dd90e193b55e8764
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/autotest/+/3191031
Reviewed-by: Jeremy Bettis <[email protected]>
Reviewed-by: Tom Hughes <[email protected]>
Tested-by: Kshitij Shah <[email protected]>
Commit-Queue: Kshitij Shah <[email protected]>
diff --git a/server/site_tests/firmware_ECUpdateId/control b/server/site_tests/firmware_ECUpdateId/control
index efdbdca..93f53df 100644
--- a/server/site_tests/firmware_ECUpdateId/control
+++ b/server/site_tests/firmware_ECUpdateId/control
@@ -15,6 +15,7 @@
 TEST_TYPE = "server"
 JOB_RETRIES = 0
 DEPENDENCIES = "ec:cros, servo_state:WORKING"
+PY_VERSION = 3
 
 DOC = """
 This test modifies the EC ID in AP firmware, reboots EC, and checks the next