Refactor `src/libs/actions/Policy/Policy.ts` to remove `Onyx.connect()` references

This is part of deprecating Onyx.connect. [Parent Issue](https://github.com/Expensify/Expensify/issues/522215)

Module: [src/libs/actions/Policy/Policy.ts](https://github.com/Expensify/App/blob/main/src/libs/actions/Policy/Policy.ts)

This issue tracks the refactoring of `Onyx.connect` references in `src/libs/actions/Policy/Policy.ts`.