defaultValues with useForm call setValueAs twice, one time with invalid input

[avallete]

Describe the bug
When using defaultValues with a field having a setValueAs function defined, setValueAs is called twice, causing the form to fail dispatching a proper value if the return of setValueAs is not a valid input for the field.

To Reproduce

1. Go to https://codesandbox.io/s/wandering-moon-hry9x?file=/src/App.js
2. Open the console, you'll see that "nullableDate" has been called twice using defaultValues. Once with a string, a second time with a Date object. Causing the default value to not be displayed inside the input field of type "date" (which expect a value like: "2021-01-01")
3. Uncomment the code from line: 25-31, reload the page.
4. setValueAs has been called once with a string as input as expected.

Codesandbox link (Required)
https://codesandbox.io/s/wandering-moon-hry9x?file=/src/App.js