Update ALS setup doc as istio 1.3 released (#3470)

* Update als_setting.md

* Update als_setting.md

docs/en/setup/envoy/als_setting.md

@@ -2,28 +2,12 @@
 Envoy [ALS(access log service)](https://www.envoyproxy.io/docs/envoy/latest/api-v2/service/accesslog/v2/als.proto) provides
 fully logs about RPC routed, including HTTP and TCP.
 
+**If solution initialized and first implemented by [Sheng Wu](https://github.com/wu-sheng), [Hongtao Gao](https://github.com/hanahmily), [Lizan Zhou](https://github.com/lizan) and [Dhi Aurrahman](https://github.com/dio) at 17 May. 2019, and presented on [KubeCon China 2019](https://kccncosschn19eng.sched.com/event/NroB/observability-in-service-mesh-powered-by-envoy-and-apache-skywalking-sheng-wu-lizan-zhou-tetrate).**
+
+SkyWalking is the first open source project introducing this ALS based solution to the world. This provides a new way with very low payload to service mesh, but the same observability.
+
 You need three steps to open ALS.
-1. Open envoyAccessLogService at istio. See [more](https://github.com/istio/istio/blob/22198bd29b224139b9614fe506e5c07716928031/install/kubernetes/helm/istio/values.yaml#L179)
-on istio helm chart.
-```yaml
-    # Configure envoy gRPC access log service.
-    envoyAccessLogService:
-      enabled: false
-      host: # example: accesslog-service.istio-system
-      port: # example: 15000
-      tlsSettings:
-        mode: DISABLE # DISABLE, SIMPLE, MUTUAL, ISTIO_MUTUAL
-        clientCertificate: # example: /etc/istio/als/cert-chain.pem
-        privateKey: # example: /etc/istio/als/key.pem
-        caCertificates: # example: /etc/istio/als/root-cert.pem
-        sni: # example: als.somedomain
-        subjectAltNames: []
-        # - als.somedomain 
-      tcpKeepalive:
-        probes: 3
-        time: 10s
-        interval: 10s
-```
+1. Open envoyAccessLogService in istio by [enabling **envoyAccessLogService** in ProxyConfig](https://istio.io/docs/reference/config/istio.mesh.v1alpha1/#ProxyConfig).
 2. Open SkyWalking [envoy receiver](../backend/backend-receivers.md).
 3. Active ALS k8s-mesh analysis
 ```yaml
@@ -33,5 +17,4 @@ envoy-metric:
       - k8s-mesh
 ```
 
-Notice, only use this when using envoy under Istio controlled.
-Otherwise, you need to implement your own `ALSHTTPAnalysis` and register it to receiver.
\ No newline at end of file
+Notice, only use this when envoy under Istio controlled, also in k8s env.