[Feature Request] Update schedule default values

[cretz]

Describe the solution you'd like

Per https://github.com/temporalio/api/pull/308, https://github.com/temporalio/sdk-python/blob/3796ec3e4039b61eb79e143aee815c6448134d39/temporalio/client.py#L3579 should now be 1 year. Also, consider if we can have defaults be server-side defaults instead of client-side (changes types to make it seem like this value is optional when it's not). Will discuss with team.