NIFI-9251 Added AuthenticationManager Bean to avoid unnecessary password generation

Signed-off-by: Pierre Villard <pierre.villard.fr@gmail.com>

This closes #5416.
diff --git a/nifi-registry/nifi-registry-core/nifi-registry-web-api/src/main/java/org/apache/nifi/registry/web/security/NiFiRegistrySecurityConfig.java b/nifi-registry/nifi-registry-core/nifi-registry-web-api/src/main/java/org/apache/nifi/registry/web/security/NiFiRegistrySecurityConfig.java
index d1b6012..8525727 100644
--- a/nifi-registry/nifi-registry-core/nifi-registry-web-api/src/main/java/org/apache/nifi/registry/web/security/NiFiRegistrySecurityConfig.java
+++ b/nifi-registry/nifi-registry-core/nifi-registry-web-api/src/main/java/org/apache/nifi/registry/web/security/NiFiRegistrySecurityConfig.java
@@ -30,7 +30,9 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.security.authentication.AuthenticationManager;
 import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder;
 import org.springframework.security.config.annotation.method.configuration.EnableGlobalMethodSecurity;
 import org.springframework.security.config.annotation.web.builders.HttpSecurity;
@@ -137,6 +139,17 @@
                 .authenticationProvider(jwtAuthenticationProvider());
     }
 
+    /**
+     * Provide Authentication Manager Bean to disable unnecessary UserDetailsServiceAutoConfiguration
+     * @return Authentication Manager
+     * @throws Exception Thrown when failing to initialize Authentication Manager
+     */
+    @Bean
+    @Override
+    public AuthenticationManager authenticationManagerBean() throws Exception {
+        return super.authenticationManagerBean();
+    }
+
     private IdentityFilter x509AuthenticationFilter() throws Exception {
         if (x509AuthenticationFilter == null) {
             x509AuthenticationFilter = new IdentityFilter(x509IdentityProvider);