Wifi usability:  Add IP reachability lost into Wifi unusable event

IP reachability is a strong indicator of Wi-Fi network quality. Extend
the WifiIsUnusableEvent list to include IP reachability lost.

Bug: 129282057
Test: frameworks/base/wifi/tests/runtests.sh

Change-Id: I0ff1075d619073d19fa365a1e6fc9894a109b8e9
Signed-off-by: Mingguang Xu <mingguangxu@google.com>
diff --git a/proto/src/wifi.proto b/proto/src/wifi.proto
index 1bcc888..e2cd9c0 100644
--- a/proto/src/wifi.proto
+++ b/proto/src/wifi.proto
@@ -1752,6 +1752,9 @@
 
     // Firmware generated an alert
     TYPE_FIRMWARE_ALERT = 4;
+
+    // IP Manager lost reachability to network neighbors
+    TYPE_IP_REACHABILITY_LOST = 5;
   }
 
   // What event triggered WifiIsUnusableEvent.
@@ -2041,6 +2044,9 @@
 
     // Firmware generated an alert
     TYPE_FIRMWARE_ALERT = 4;
+
+    // IP Manager lost reachability to network neighbors
+    TYPE_IP_REACHABILITY_LOST = 5;
   }
 
   // The current wifi usability state