Add support for context to net-lb-int net-vpc-firewall and net-vpc module (#3419)

* net-lb-int

* net-vpc-firewall

* net-vpc

* net-vpc

tests/modules/net_vpc_firewall/context.tfvars

@@ -0,0 +1,47 @@
+context = {
+  cidr_ranges = {
+    rfc1918-10 = "10.0.0.0/8"
+  }
+  iam_principals = {
+    test = "serviceAccount:test@test-project.iam.gserviceaccount.com"
+  }
+  networks = {
+    test = "projects/foo-dev-net-spoke-0/global/networks/dev-spoke-0"
+  }
+  project_ids = {
+    test = "foo-test-0"
+  }
+}
+project_id = "$project_ids:test"
+network    = "$networks:test"
+attachments = {
+  test = "$networks:test"
+}
+default_rules_config = {
+  admin_ranges = ["$cidr_ranges:rfc1918-10"]
+  http_ranges  = ["$cidr_ranges:rfc1918-10"]
+  https_ranges = ["$cidr_ranges:rfc1918-10"]
+  ssh_ranges   = ["$cidr_ranges:rfc1918-10"]
+}
+egress_rules = {
+  allow-egress-rfc1918 = {
+    deny        = false
+    description = "Allow egress."
+    destination_ranges = [
+      "$cidr_ranges:rfc1918-10", "172.16.0.0/12", "192.168.0.0/16"
+    ]
+    source_ranges        = ["$cidr_ranges:rfc1918-10"]
+    targets              = ["$iam_principals:test"]
+    use_service_accounts = true
+  }
+}
+ingress_rules = {
+  allow-ingress-tag = {
+    description          = "Allow ingress."
+    destination_ranges   = ["$cidr_ranges:rfc1918-10"]
+    source_ranges        = ["$cidr_ranges:rfc1918-10"]
+    sources              = ["$iam_principals:test"]
+    targets              = ["$iam_principals:test"]
+    use_service_accounts = true
+  }
+}