Increase gradle version to 3.15.5
Increase gradle version to 3.15.5

Nike-Inc/cerberus-management-service,Nike-Inc/cerberus,Nike-Inc/cerberus-management-service,Nike-Inc/cerberus,Nike-Inc/cerberus-management-service,Nike-Inc/cerberus-management-service,Nike-Inc/cerberus,Nike-Inc/cerberus