Increase the client timeout to 10m (#23839) (#25498)

* Fixes a timeout error when the client and Fleet Server both have 5 mins
  timeout and client times out before the server request.
  The Fleet server should drive the request timeout for long poll.

(cherry picked from commit 6a0aec0)

Co-authored-by: Aleksandr Maus <aleksandr.maus@elastic.co>

x-pack/elastic-agent/pkg/remote/config.go

@@ -53,8 +53,9 @@ func DefaultClientConfig() Config {
 		SpaceID:  "",
 		Username: "",
 		Password: "",
-		Timeout:  5 * time.Minute,
-		TLS:      nil,
+		// Default timeout 10 minutes, expecting Fleet Server to control the long poll with default timeout of 5 minutes
+		Timeout: 10 * time.Minute,
+		TLS:     nil,
 	}
 }