allow to customize awsName

[g-traveller]

Describe the feature

Flagger doesn't allow user to customze awsName, the awsName is created with default value "${name}.${namespace}" of k8s VirtualService, in some cases, it means the code must be changed to adapt this pattern (${name}.${namespace})

Proposed solution

Add a propery in Canary configuration to allow user can customize their awsName