Add missing envars

Author: farski

spire/templates/apps/exchange.yml

@@ -1450,6 +1450,8 @@ Resources:
           EXCHANGE_HOSTNAME: !Ref ExchangeHostname
           MYSQL_ENDPOINT: !Ref SharedAuroraMysqlEndpoint
           APP_ENVIRONMENT: !Ref EnvironmentTypeLowercase
+          MEDIAJOINT_S3_BUCKET_ARN: !Ref MediajointS3BucketArn
+          ENCRYPTION_SECRET_PARAMETER_ARN: !Sub arn:aws:ssm:${AWS::Region}:${AWS::AccountId}:parameter/prx/${EnvironmentTypeAbbreviation}/Spire/Exchange/ftp-auth-capture-encryption-secret
       Handler: index.handler
       MemorySize: 128
       Policies: