Use a static getter to fetch the preferred payment setting

We need to use this from the system server before the NFC service has
started. This makes getting an instance of `CardEmulation` difficult, so
instead make it into a static method and access the setting directly
instead of via the service.

Bug: 321098555
Test: manual,NFC CTS tests
Change-Id: I92e7cfeb595a13b8d544b4a3169601748fef7101