Change Alicloud EIP type PayByTraffic

[jia-jerry]

What this PR does / why we need it:
Change Alicloud EIP type PayByTraffic. It will save a lot of money. Origin setup was charged more than 1/2 of VM instances!!!

Gardener does now create Alicloud EIPs with `PayByTraffic` policy for new clusters to save costs.

[rfranzke]

As discussed via Slack: It won't work that way. You can only do that for new shoots. Check in the Alicloud Botanist whether the Terraform config already exists (if yes, then preserve old logic (PayByBandWidth). Otherwise, go ahead with PayByTraffic.

[rfranzke]

/cc @adracus

This should be taken over into the Alicloud extension infrastructure controller ⚠️

[jia-jerry]

As discussed via Slack: It won't work that way. You can only do that for new shoots. Check in the Alicloud Botanist whether the Terraform config already exists (if yes, then preserve old logic (PayByBandWidth). Otherwise, go ahead with PayByTraffic.

Hi @rfranzke , Now we will keep old pay type for exsiting shoot. The new shoot will use PayByTraffic.

[rfranzke]

/lgtm