passpoint-r2: change return type of getAllMatchingWifiConfigs

It is to get the scanresults per home or roaming network type for
matching PasspointProfile.
With this, UI is able to connect to an AP based on the following priority.
1) Home network
2) Roaming network

Bug: 119514793
Test: ./frameworks/base/wifi/tests/runtests.sh
Change-Id: I88cacddc072d04e478536276dee411ecc63ced52
Signed-off-by: Ecco Park <eccopark@google.com>