Wifi: Add HAL API and implementation for instant mode filter

Bug: 203220137
Test: pass vts test
Change-Id: I7f4d9d4390ad69bcfdb2419c2e172c4df2d6863b
diff --git a/wifi/1.6/default/hidl_struct_util.cpp b/wifi/1.6/default/hidl_struct_util.cpp
index eeea6ef..76341ff 100644
--- a/wifi/1.6/default/hidl_struct_util.cpp
+++ b/wifi/1.6/default/hidl_struct_util.cpp
@@ -433,6 +433,9 @@
     if (hidl_filter_mask & V1_5::IWifiChip::UsableChannelFilter::CONCURRENCY) {
         legacy_filter_mask |= legacy_hal::WIFI_USABLE_CHANNEL_FILTER_CONCURRENCY;
     }
+    if (hidl_filter_mask & V1_6::IWifiChip::UsableChannelFilter::NAN_INSTANT_MODE) {
+        legacy_filter_mask |= WIFI_USABLE_CHANNEL_FILTER_NAN_INSTANT_MODE;
+    }
     return legacy_filter_mask;
 }