Add fix + regression test for null disconnectReason in onConnectionInterrupted.

libsignal-service/src/main/java/org/whispersystems/signalservice/internal/websocket/LibSignalChatConnection.kt

@@ -379,7 +379,7 @@ class LibSignalChatConnection(
       incomingRequestQueue.put(incomingWebSocketRequest)
     }
 
-    override fun onConnectionInterrupted(chat: ChatConnection, disconnectReason: ChatServiceException) {
+    override fun onConnectionInterrupted(chat: ChatConnection, disconnectReason: ChatServiceException?) {
       CHAT_SERVICE_LOCK.withLock {
         Log.i(TAG, "$name connection interrupted", disconnectReason)
         chatConnection = null

libsignal-service/src/test/java/org/whispersystems/signalservice/internal/websocket/LibSignalChatConnectionTest.kt

@@ -69,6 +69,12 @@ class LibSignalChatConnectionTest {
       delay {
         it.complete(null)
         disconnectLatch?.countDown()
+
+        // The disconnectReason is null when the disconnect is due to the local client requesting the disconnect.
+        // This is a regression test because we previously forgot to update the Kotlin type definitions to
+        //   match this when the behavior changed in libsignal-client, causing NullPointerExceptions
+        //   missed connection interrupted events.
+        chatListener!!.onConnectionInterrupted(chatConnection, null)
       }
     }