Set default value to 'false' for 'isOAuth2ConfigAllowed'

dao/src/main/java/org/thingsboard/server/dao/oauth2/OAuth2ServiceImpl.java

@@ -129,7 +129,7 @@ public class OAuth2ServiceImpl extends AbstractEntityService implements OAuth2Se
         if (tenant == null) return false;
         JsonNode allowOAuth2ConfigurationJsonNode = tenant.getAdditionalInfo() != null ? tenant.getAdditionalInfo().get(ALLOW_OAUTH2_CONFIGURATION) : null;
         if (allowOAuth2ConfigurationJsonNode == null) {
-            return true;
+            return false;
         } else {
             return allowOAuth2ConfigurationJsonNode.asBoolean();
         }

dao/src/test/java/org/thingsboard/server/dao/service/BaseOAuth2ServiceTest.java

@@ -66,7 +66,7 @@ public class BaseOAuth2ServiceTest extends AbstractServiceTest {
     @Test
     public void testIsOAuth2Allowed_null() throws IOException {
         updateTenantAllowOAuth2Setting(null);
-        Assert.assertTrue(oAuth2Service.isOAuth2ClientRegistrationAllowed(tenantId));
+        Assert.assertFalse(oAuth2Service.isOAuth2ClientRegistrationAllowed(tenantId));
     }
 
     @Test