wifi: Move SAP passphrase ascii encodable check to wifi-service

Add new overlay config to allow OEM bypass SAP passphrase ascii
encodable check since it depends on HAL and driver.

Bug: 168688691
Test: atest FrameworksWifiApiTests
Test: Manual test to add non ascii passphrase
Change-Id: If573acece96faf59c7804c6178d0f0200164f88e