wifi: always return non-null value from generateSecurityParamsListFromScanResult

The returned list is used for iterations and some validation check,
returning null increases unnecessary null checks for iterations and
might result in unexpected NPE.

Bug: 184789513
Test: atest FrameworksWifiTests
Change-Id: Ieecc5d144c804de21ff6ad9a3ff5a868cd1d5387
1 file changed