fix: typo in TransportOptions option name (#530)

Author: bshaffer

src/Options/ClientOptions.php

@@ -168,7 +168,7 @@ private function fromArray(array $arr): void
         $this->setApiEndpoint($arr['apiEndpoint'] ?? null);
         $this->setDisableRetries($arr['disableRetries'] ?? false);
         $this->setClientConfig($arr['clientConfig'] ?? []);
-        $this->setCredentials($arr['credentials']);
+        $this->setCredentials($arr['credentials'] ?? null);
         $this->setCredentialsConfig($arr['credentialsConfig'] ?? []);
         $this->setTransport($arr['transport'] ?? null);
         $this->setTransportConfig(new TransportOptions($arr['transportConfig'] ?? []));

src/Options/TransportOptions.php

@@ -69,7 +69,7 @@ public function __construct(array $options)
     private function fromArray(array $arr): void
     {
         $this->setGrpc(new GrpcTransportOptions($arr['grpc'] ?? []));
-        $this->setGrpcFallback(new GrpcFallbackTransportOptions($arr['grpc-fallack'] ?? []));
+        $this->setGrpcFallback(new GrpcFallbackTransportOptions($arr['grpc-fallback'] ?? []));
         $this->setRest(new RestTransportOptions($arr['rest'] ?? []));
     }