WiFi: Get channel stats from linklayer radio stats

Get the list of channel stats from linklayerstats radiostats
and send it to framework.

Bug: 79111545
Test: Connected STA to AP and verified the link layer stats
Test: Unit test
Test: ./wifi/1.3/default/tests/runtests.sh
Change-Id: If1008256afe0ec918cdbd952aa4f14012d5b0caf
diff --git a/wifi/1.3/default/wifi_legacy_hal.h b/wifi/1.3/default/wifi_legacy_hal.h
index af654fa..d1687a3 100644
--- a/wifi/1.3/default/wifi_legacy_hal.h
+++ b/wifi/1.3/default/wifi_legacy_hal.h
@@ -61,6 +61,7 @@
 struct LinkLayerRadioStats {
     wifi_radio_stat stats;
     std::vector<uint32_t> tx_time_per_levels;
+    std::vector<wifi_channel_stat> channel_stats;
 };
 
 struct LinkLayerStats {