Support MTU change for VPC

[kkskumar7]

/kind feature

Describe the solution you'd like
[A clear and concise description of what you want to happen.]

As of now, CAPG doesn't allow to set MTU for VPC which creates a VPC with default MTU as 1460. So option needs to be available to change MTU to different value.

Anything else you would like to add:
[Miscellaneous information that will assist in solving the issue.]

[tasdikrahman]

/assign