[Android] Add known devices flag for host_info.

testing/scripts/host_info.py

Index: testing/scripts/host_info.py
diff --git a/testing/scripts/host_info.py b/testing/scripts/host_info.py
index 37fa54b4ebdd5f9beb1689a2a9356742c328d3a4..deaa439c497124d8a228beffcd15d266a191efcb 100755
--- a/testing/scripts/host_info.py
+++ b/testing/scripts/host_info.py
@@ -57,8 +57,8 @@ def get_device_info(args, failures):
     return {}
 
   with common.temporary_file() as tempfile_path:
-    rc = common.run_command([
-        sys.executable,
+    test_cmd = [
+        sys.executeable,

[shatch, 2016/08/04 16:47:02]

Is this right?

[rnephew (Reviews Here), 2016/08/04 16:50:48]

Would you believe me if I said yes?
Fixed.

[shatch, 2016/08/04 16:58:02]

haha

         os.path.join(args.paths['checkout'],
                      'third_party',
                      'catapult',
@@ -69,8 +69,12 @@ def get_device_info(args, failures):
                      'device_status.py'),
         '--json-output', tempfile_path,
         '--blacklist-file', os.path.join(
-            args.paths['checkout'], 'out', 'bad_devices.json')])
+              args.paths['checkout'], 'out', 'bad_devices.json')
+    ]
+    if args.known_devices_file:
+      test_cmd.extend(['--known-devices-file', args.known_devices_file])
 
+    rc = common.run_command(test_cmd)
     if rc:
       failures.append('device_status')
       return {}