wifi: Add SAP generation indication API

Bug: 151189102
Test: atest FrameworksWifiApiTests
Change-Id: I8cd1b21029f42784f72499d9cc8bed392f6dd175
diff --git a/wifi/api/system-current.txt b/wifi/api/system-current.txt
index eff64a3..d84abb5 100644
--- a/wifi/api/system-current.txt
+++ b/wifi/api/system-current.txt
@@ -292,6 +292,7 @@
     method public int getBandwidth();
     method @Nullable public android.net.MacAddress getBssid();
     method public int getFrequency();
+    method public int getWifiStandard();
     method public void writeToParcel(@NonNull android.os.Parcel, int);
     field public static final int CHANNEL_WIDTH_160MHZ = 6; // 0x6
     field public static final int CHANNEL_WIDTH_20MHZ = 2; // 0x2