Fix minor RBAC/auth NPEs, init null collections (#3185)

kafka-ui-api/src/main/java/com/provectus/kafka/ui/config/auth/OAuthProperties.java

@@ -1,6 +1,7 @@
 package com.provectus.kafka.ui.config.auth;
 
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.Map;
 import java.util.Set;
 import javax.annotation.PostConstruct;
@@ -31,13 +32,13 @@ public class OAuthProperties {
     private String clientName;
     private String redirectUri;
     private String authorizationGrantType;
-    private Set<String> scope;
+    private Set<String> scope = new HashSet<>();
     private String issuerUri;
     private String authorizationUri;
     private String tokenUri;
     private String userInfoUri;
     private String jwkSetUri;
     private String userNameAttribute;
-    private Map<String, String> customParams;
+    private Map<String, String> customParams = new HashMap<>();
   }
 }

kafka-ui-api/src/main/java/com/provectus/kafka/ui/config/auth/OAuthPropertiesConverter.java

@@ -71,7 +71,7 @@ public final class OAuthPropertiesConverter {
   }
 
   private static boolean isGoogle(OAuth2Provider provider) {
-    return provider.getCustomParams().get(TYPE).equalsIgnoreCase(GOOGLE);
+    return GOOGLE.equalsIgnoreCase(provider.getCustomParams().get(TYPE));
   }
 }