Fix gitlab_ui_checkbox_component when { multiple: true }

What does this MR do and why?

This fix is needed for !80131 (merged) as part of gitlab-org/growth/team-tasks#461 (closed)

When { multiple: true } option is passed to check_box it suffixes the input's id attribute value with checked_value. For example:

-# checked_value = "dog"
= f.check_box(:pets, { multiple: true}, 'dog')

=> <input type="checkbox" id="user_pets_dog" name="user[pets][]" value="dog" />

Previous implementation does not pass in a value parameter to generic_label so the resulting <label /> has the incorrect for attribute value. This makes the resulting checkboxes un-checkable since the labels are not properly matched with the right inputs.

= f.gitlab_ui_checkbox_component(:pets, 'Dog', checked_value: 'dog', checkbox_options: { multiple: true})

=> -# input's id and label's for do not match
   <input type="checkbox" id="user_pets_dog" name="user[pets][]" value="dog" />
   <label for="user_pets">Dog</label>

This MR updates gitlab_ui_checkbox_component such that when { multiple: true } is passed in as one of checkbox_options we pass in checked_value as value param to generic_label to create <label />s with correct for attribute values.

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Screen_Recording_2022-02-09_at_10.16.34_AM	Screen_Recording_2022-02-09_at_10.14.36_AM

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