fix the bug of authenticationData is't initialized. (#6440)

Motivation
fix the bug of authenticationData is't initialized.

the method org.apache.pulsar.proxy.server.ProxyConnection#handleConnect can't init the value of authenticationData.
cause of the bug that you will get the null value form the method org.apache.pulsar.broker.authorization.AuthorizationProvider#canConsumeAsync
when implements org.apache.pulsar.broker.authorization.AuthorizationProvider interface.

Modifications
init the value of authenticationData from the method org.apache.pulsar.proxy.server.ProxyConnection#handleConnect.

Verifying this change
implements org.apache.pulsar.broker.authorization.AuthorizationProvider interface， and get the value of authenticationData.

(cherry picked from commit b8f0ca09)

pulsar-proxy/src/main/java/org/apache/pulsar/proxy/server/ProxyConnection.java

@@ -327,6 +327,7 @@ public class ProxyConnection extends PulsarHandler implements FutureListener<Voi
             }
 
             authState = authenticationProvider.newAuthState(clientData, remoteAddress, sslSession);
+            authenticationData = authState.getAuthDataSource();
             doAuthentication(clientData);
         } catch (Exception e) {
             LOG.warn("[{}] Unable to authenticate: ", remoteAddress, e);