wifi: add default HIDL service init RC

Before transiting to this defeault service, any target-specific
parameters must be moved to the overlay file.

Once the cmdline matches this default service, define
WIFI_HIDL_UNIFIED_SUPPLICANT_SERVICE_RC_ENTRY in BoardConfig
to transite to this default HIDL service seamlessly.

Bug: 138790309
Test: verify wifi basic functions
Change-Id: I3ae90734b58c5c1206bd34a0b0c6080bdd7a7553
2 files changed