[CT-2698] use_approximate_percentile and use_discrete_percentile keys defualt to None but are defined as bool in the protocol

[Jstein77]

Is this a new bug in dbt-core?

• I believe this is a new bug in dbt-core
• I have searched the existing issues, and I could not find an existing issue for this bug

Current Behavior

The default None for use_approximate_percentile and use_discrete_percentile causes an error. I need to define the bool value for these parameters in the measure. However, I should only assign true or false to these parameters if I need to use them, and they should default to false.

Current implementation:

- name: discrete_order_value_p99
        expr: order_total
        agg: percentile
        agg_params:
          percentile: 0.99
          use_discrete_percentile: True
          use_approximate_percentile: False
        create_metric: true

Expected implementation:

- name: discrete_order_value_p99
        expr: order_total
        agg: percentile
        agg_params:
          percentile: 0.99
          use_discrete_percentile: True
        create_metric: true

Expected Behavior

I should not need to define true or false explicitly for use_discrete_percentile and use_approximate_percentile. They should default to false.

Steps To Reproduce

Define a measure like below and run dbt run.

- name: discrete_order_value_p99
        expr: order_total
        agg: percentile
        agg_params:
          percentile: 0.99
          use_discrete_percentile: True
        create_metric: true

Relevant log output

No response

Environment

- OS:
- Python:
- dbt:

Which database adapter are you using with dbt?

No response

Additional Context

No response

[Jstein77]

cc @QMalcolm