"Undefined index: expires" error when installing on site upgraded from Craft 2

[rsanchez]

Encountered in the midst of an upgrade from Craft 2:

$ ./craft install/plugin aws-s3
*** installing aws-s3
Exception: Undefined index: expires (<redacted>/ew-craftcms/vendor/craftcms/aws-s3/src/migrations/Install.php:72)
#0 <redacted>/ew-craftcms/vendor/craftcms/aws-s3/src/migrations/Install.php(72): yii\base\ErrorHandler->handleError(8, 'Undefined index...', '/Users/robsanch...', 72, Array)
#1 <redacted>/ew-craftcms/vendor/craftcms/aws-s3/src/migrations/Install.php(33): craft\awss3\migrations\Install->_convertVolumes()
#2 <redacted>/ew-craftcms/vendor/craftcms/cms/src/db/Migration.php(58): craft\awss3\migrations\Install->safeUp()
#3 <redacted>/ew-craftcms/vendor/craftcms/cms/src/db/MigrationManager.php(239): craft\db\Migration->up(true)
#4 <redacted>/ew-craftcms/vendor/craftcms/cms/src/base/Plugin.php(155): craft\db\MigrationManager->migrateUp(Object(craft\awss3\migrations\Install))
#5 <redacted>/ew-craftcms/vendor/craftcms/cms/src/services/Plugins.php(520): craft\base\Plugin->install()
#6 <redacted>/ew-craftcms/vendor/craftcms/cms/src/console/controllers/InstallController.php(195): craft\services\Plugins->installPlugin('aws-s3')
#7 [internal function]: craft\console\controllers\InstallController->actionPlugin('aws-s3')
#8 <redacted>/ew-craftcms/vendor/yiisoft/yii2/base/InlineAction.php(57): call_user_func_array(Array, Array)
#9 <redacted>/ew-craftcms/vendor/yiisoft/yii2/base/Controller.php(157): yii\base\InlineAction->runWithParams(Array)
#10 <redacted>/ew-craftcms/vendor/yiisoft/yii2/console/Controller.php(164): yii\base\Controller->runAction('plugin', Array)
#11 <redacted>/ew-craftcms/vendor/craftcms/cms/src/console/Controller.php(199): yii\console\Controller->runAction('plugin', Array)
#12 <redacted>/ew-craftcms/vendor/yiisoft/yii2/base/Module.php(528): craft\console\Controller->runAction('plugin', Array)
#13 <redacted>/ew-craftcms/vendor/yiisoft/yii2/console/Application.php(180): yii\base\Module->runAction('install/plugin', Array)
#14 <redacted>/ew-craftcms/vendor/craftcms/cms/src/console/Application.php(93): yii\console\Application->runAction('install/plugin', Array)
#15 <redacted>/ew-craftcms/vendor/yiisoft/yii2/console/Application.php(147): craft\console\Application->runAction('install/plugin', Array)
#16 <redacted>/ew-craftcms/vendor/yiisoft/yii2/base/Application.php(386): yii\console\Application->handleRequest(Object(craft\console\Request))
#17 <redacted>/ew-craftcms/craft(22): yii\base\Application->run()
#18 {main}

It seems that there are some instances where the expires property is not present in the configuration array. The solution would be to check whether expires prop exist before using it.