feat(object_store): Add support for session token in AWS credentials

- Pass session token, either null or with value, to the AWS Credentials constructor

Signed-off-by: Hector Valcarcel <hmvalcarcel@gmail.com>

AUTHORS

@@ -560,6 +560,7 @@
  - fnuesse <felix.nuesse@t-online.de>
  - fnuesse <fnuesse@techfak.uni-bielefeld.de>
  - greta <gretadoci@gmail.com>
+ - Hector Valcarcel <hmvalcarcel@gmail.com>
  - helix84 <helix84@centrum.sk>
  - hkjolhede <hkjolhede@gmail.com>
  - hoellen <dev@hoellen.eu>

lib/private/Files/ObjectStore/S3ConnectionTrait.php

@@ -128,7 +128,7 @@ public function getConnection() {
 				$logger->debug('Bucket "' . $this->bucket . '" This bucket name is not dns compatible, it may contain invalid characters.',
 					['app' => 'objectstore']);
 			}
-	
+
 			if ($this->params['verify_bucket_exists'] && !$this->connection->doesBucketExist($this->bucket)) {
 				try {
 					$logger->info('Bucket "' . $this->bucket . '" does not exist - creating it.', ['app' => 'objectstore']);
@@ -185,10 +185,12 @@ protected function paramCredentialProvider(): callable {
 		return function () {
 			$key = empty($this->params['key']) ? null : $this->params['key'];
 			$secret = empty($this->params['secret']) ? null : $this->params['secret'];
+			$sessionToken = empty($this->params['session_token']) ? null : $this->params['session_token'];
 
 			if ($key && $secret) {
 				return Create::promiseFor(
-					new Credentials($key, $secret)
+					// a null sessionToken match the default signature of the constructor
+					new Credentials($key, $secret, $sessionToken)
 				);
 			}