Use standard lambda syntax in documentation

Fixes: gh-7774

samples/boot/hellowebflux-method/src/main/java/sample/SecurityConfig.java

@@ -40,9 +40,8 @@ public class SecurityConfig {
 		return http
 			// Demonstrate that method security works
 			// Best practice to use both for defense in depth
-			.authorizeExchange(exchanges ->
-				exchanges
-					.anyExchange().permitAll()
+			.authorizeExchange(exchanges -> exchanges
+				.anyExchange().permitAll()
 			)
 			.httpBasic(withDefaults())
 			.build();

samples/boot/helloworld/src/main/java/org/springframework/security/samples/config/SecurityConfig.java

@@ -34,15 +34,13 @@ public class SecurityConfig extends WebSecurityConfigurerAdapter {
 	@Override
 	protected void configure(HttpSecurity http) throws Exception {
 		http
-				.authorizeRequests(authorizeRequests ->
-					authorizeRequests
-						.antMatchers("/css/**", "/index").permitAll()
-						.antMatchers("/user/**").hasRole("USER")
+				.authorizeRequests(authorize -> authorize
+					.antMatchers("/css/**", "/index").permitAll()
+					.antMatchers("/user/**").hasRole("USER")
 				)
-				.formLogin(formLogin ->
-					formLogin
-						.loginPage("/login")
-						.failureUrl("/login-error")
+				.formLogin(formLogin -> formLogin
+					.loginPage("/login")
+					.failureUrl("/login-error")
 				);
 	}
 	// @formatter:on