fix: 🐛 credential library serializer for SSH certificate (#2790)

✅ Closes: https://hashicorp.atlassian.net/browse/ICU-16880

addons/api/addon/serializers/credential-library.js

@@ -28,6 +28,7 @@ export default class CredentialLibrarySerializer extends ApplicationSerializer {
       case TYPE_CREDENTIAL_LIBRARY_VAULT_GENERIC:
         return this.serializeVaultGeneric(...arguments);
       case TYPE_CREDENTIAL_LIBRARY_VAULT_SSH_CERTIFICATE:
+        return this.serializeVaultSshCertificate(...arguments);
       default:
         return super.serialize(...arguments);
     }
@@ -61,4 +62,16 @@ export default class CredentialLibrarySerializer extends ApplicationSerializer {
       return serialized;
     }
   }
+
+  serializeVaultSshCertificate() {
+    const serialized = super.serialize(...arguments);
+    if (serialized.attributes) {
+      const { key_type } = serialized.attributes;
+      if (key_type !== 'rsa' && key_type !== 'ecdsa') {
+        // If the key type is not RSA or ECDSA, set key_bits to null
+        serialized.attributes.key_bits = null;
+      }
+      return serialized;
+    }
+  }
 }