Use 5g rssi threshold by default

Before we find a solution for b/36121542, use 5g rssi threshold by
default. Since 5g rssi threshold is higher than that for 2.4g, the
phone will be less likely to be waken up frequently.

Bug: 36121542
Test: compile, unit tests, manual test

Change-Id: I8de1bcf0564edfa8597f35d62b743c506cdddf4b
diff --git a/scanning/scanner_impl.cpp b/scanning/scanner_impl.cpp
index df0c722..a9b942d 100644
--- a/scanning/scanner_impl.cpp
+++ b/scanning/scanner_impl.cpp
@@ -242,7 +242,7 @@
   if (!scan_utils_->StartScheduledScan(interface_index_,
                                        pno_settings.interval_ms_,
                                        // TODO: honor both rssi thresholds.
-                                       pno_settings.min_2g_rssi_,
+                                       pno_settings.min_5g_rssi_,
                                        request_random_mac,
                                        scan_ssids,
                                        match_ssids,