provider/google: Support static private IP addresses (#6310)
provider/google: Support static private IP addresses (#6310)

* provider/google: Support static private IP addresses

The private address of an instance's network interface may now be specified.
If no value is provided, an address will be chosen by Google Compute Engine
and that value will be read into Terraform state.

* docs: GCE private static IP address information

terraform-providers/terraform-provider-google,hashicorp/terraform-provider-google,ubschmidt2/terraform-provider-google,terraform-providers/terraform-provider-google,rosbo/terraform-provider-google,hashicorp/terraform-provider-google-beta,hashicorp/terraform-provider-google-beta,ubschmidt2/terraform-provider-google,hashicorp/terraform-provider-google,rosbo/terraform-provider-google,drebes/terraform-provider-google,nickithewatt/terraform-provider-google,nickithewatt/terraform-provider-google,drebes/terraform-provider-google,rosbo/terraform-provider-google,selmanj/terraform-provider-google,terraform-providers/terraform-provider-google,nickithewatt/terraform-provider-google,selmanj/terraform-provider-google,rosbo/terraform-provider-google,hashicorp/terraform-provider-google,drebes/terraform-provider-google,hashicorp/terraform-provider-google-beta,selmanj/terraform-provider-google,hashicorp/terraform-provider-google-beta,drebes/terraform-provider-google,hashicorp/terraform-provider-google,ubschmidt2/terraform-provider-google,terraform-providers/terraform-provider-google,terraform-providers/terraform-provider-google,ubschmidt2/terraform-provider-google