metrics: identifying dfs from non dfs scans

These data can be used to optimize power savings, since scanning dfs
channels require significantly more energy.

Bug: 72755722
Test: compile, run ./frameworks/base/wifi/tests/runtests.sh
Change-Id: Ic0515ceca452459446b245d93620885b1ade823f
diff --git a/proto/src/wifi.proto b/proto/src/wifi.proto
index ce1dd50..b2a3adf 100644
--- a/proto/src/wifi.proto
+++ b/proto/src/wifi.proto
@@ -429,6 +429,9 @@
   // The number of times wifi experienced failures after watchdog has already been triggered and is
   // waiting for a connection success
   optional int64 watchdog_total_connection_failure_count_after_trigger = 108;
+
+  // Number of times DFS channel scans are requested in single scan requests.
+  optional int32 num_oneshot_has_dfs_channel_scans = 109;
 }
 
 // Information that gets logged for every WiFi connection.