atc-installer: configure validation webhook timeout

[davidmdm]

Currently there are no options for setting the validation webhooks timeout, which forces a default of 10s.

Allow the user to set this timeout when installing the ATC.

[alam-cloud]

HI David!
Would love to have a look at this!
Warm regards
Alam

[davidmdm]

Yeah absolutely. This is a great one to pick up.

Essentially we went the user to be able to configure their desired admission webhook timeout.

The design has changed a little bit since this issue was opened.

The resources are now created and managed by the ATC on startup. So the ATC needs to accept env variables for this configuration.

The installer should then be able to set these variables conveniently.

If you need any specific guidance feel free to ask!