[Checkbox] Checkbox.md—There is a wrong code guide in the document

[MHSgulu]

Description: In the code guidance for subjecting checkboxes, an extra symbol (color attribute) appears in one of the codes, causing an error

Expected behavior: Screenshots and/or description of expected behavior

Source code: The code snippet which is causing this issue. Please consider attaching a minimal sample app that reproduces the issue.

Android API version: Android API version here

Material Library version: Material Android Library version you are using here (e.g., 1.1.0-alpha07)

Device: Device on which the bug was encountered here

To help us triage faster, please check to make sure you are using the latest version of the library.

We also happily accept pull requests.

[leticiarossi]

Thanks for catching that! Will submit a fix soon