chore(billingbudgets): add comments to proto files (via synth) (#9854)

Author: yoshi-automation

packages/google-cloud-billing-budgets/google/cloud/billing_budgets_v1beta1/proto/budget_service.proto

@@ -41,6 +41,8 @@ service BudgetService {
   rpc CreateBudget(CreateBudgetRequest) returns (Budget) {
     option (google.api.http) = {
       post: "/v1beta1/{parent=billingAccounts/*}/budgets"
+      // (-- TODO for GA: use "budget" instead of "*" to comply with
+      // https://aip.dev/133. Changing in Beta would be a breaking change. --)
       body: "*"
     };
   }
@@ -49,6 +51,8 @@ service BudgetService {
   rpc UpdateBudget(UpdateBudgetRequest) returns (Budget) {
     option (google.api.http) = {
       patch: "/v1beta1/{budget.name=billingAccounts/*/budgets/*}"
+      // (-- TODO for GA: use "budget" instead of "*" to comply with
+      // https://aip.dev/134. Changing in Beta would be a breaking change. --)
       body: "*"
     };
   }

packages/google-cloud-billing-budgets/synth.metadata

@@ -1,5 +1,5 @@
 {
-  "updateTime": "2019-11-19T13:16:42.779546Z",
+  "updateTime": "2019-11-20T13:14:31.109994Z",
   "sources": [
     {
       "generator": {
@@ -12,8 +12,8 @@
       "git": {
         "name": "googleapis",
         "remote": "https://github.com/googleapis/googleapis.git",
-        "sha": "d8dd7fe8d5304f7bd1c52207703d7f27d5328c5a",
-        "internalRef": "281088257"
+        "sha": "16543773103e2619d2b5f52456264de5bb9be104",
+        "internalRef": "281423227"
       }
     },
     {