feat(cloudbilling): update the API

#### cloudbilling:v1beta

The following keys were changed:
- schemas.Decimal.description

#### cloudbilling:v1

The following keys were added:
- schemas.BillingAccount.properties.currencyCode.description
- schemas.BillingAccount.properties.currencyCode.type

Author: yoshi-automation

discovery/cloudbilling-v1.json

@@ -751,7 +751,7 @@
       }
     }
   },
-  "revision": "20240517",
+  "revision": "20241011",
   "rootUrl": "https://cloudbilling.googleapis.com/",
   "schemas": {
     "AggregationInfo": {
@@ -844,6 +844,10 @@
       "description": "A billing account in the [Google Cloud Console](https://console.cloud.google.com/). You can assign a billing account to one or more projects.",
       "id": "BillingAccount",
       "properties": {
+        "currencyCode": {
+          "description": "Optional. The currency in which the billing account is billed and charged, represented as an ISO 4217 code such as `USD`. Billing account currency is determined at the time of billing account creation and cannot be updated subsequently, so this field should not be set on update requests. In addition, a subaccount always matches the currency of its parent billing account, so this field should not be set on subaccount creation requests. Clients can read this field to determine the currency of an existing billing account.",
+          "type": "string"
+        },
         "displayName": {
           "description": "The display name given to the billing account, such as `My Billing Account`. This name is displayed in the Google Cloud Console.",
           "type": "string"

discovery/cloudbilling-v1beta.json

@@ -761,7 +761,7 @@
       }
     }
   },
-  "revision": "20240906",
+  "revision": "20241106",
   "rootUrl": "https://cloudbilling.googleapis.com/",
   "schemas": {
     "CacheFillRegions": {
@@ -1245,7 +1245,7 @@
       "type": "object"
     },
     "Decimal": {
-      "description": "A representation of a decimal value, such as 2.5. Clients may convert values into language-native decimal formats, such as Java's BigDecimal or Python's decimal.Decimal. [BigDecimal]: https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/math/BigDecimal.html [decimal.Decimal]: https://docs.python.org/3/library/decimal.html",
+      "description": "A representation of a decimal value, such as 2.5. Clients may convert values into language-native decimal formats, such as Java's [BigDecimal](https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/math/BigDecimal.html) or Python's [decimal.Decimal](https://docs.python.org/3/library/decimal.html).",
       "id": "Decimal",
       "properties": {
         "value": {

src/apis/cloudbilling/v1.ts

@@ -171,6 +171,10 @@ export namespace cloudbilling_v1 {
    * A billing account in the [Google Cloud Console](https://console.cloud.google.com/). You can assign a billing account to one or more projects.
    */
   export interface Schema$BillingAccount {
+    /**
+     * Optional. The currency in which the billing account is billed and charged, represented as an ISO 4217 code such as `USD`. Billing account currency is determined at the time of billing account creation and cannot be updated subsequently, so this field should not be set on update requests. In addition, a subaccount always matches the currency of its parent billing account, so this field should not be set on subaccount creation requests. Clients can read this field to determine the currency of an existing billing account.
+     */
+    currencyCode?: string | null;
     /**
      * The display name given to the billing account, such as `My Billing Account`. This name is displayed in the Google Cloud Console.
      */

src/apis/cloudbilling/v1beta.ts

@@ -418,7 +418,7 @@ export namespace cloudbilling_v1beta {
     virtualCpuCount?: string | null;
   }
   /**
-   * A representation of a decimal value, such as 2.5. Clients may convert values into language-native decimal formats, such as Java's BigDecimal or Python's decimal.Decimal. [BigDecimal]: https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/math/BigDecimal.html [decimal.Decimal]: https://docs.python.org/3/library/decimal.html
+   * A representation of a decimal value, such as 2.5. Clients may convert values into language-native decimal formats, such as Java's [BigDecimal](https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/math/BigDecimal.html) or Python's [decimal.Decimal](https://docs.python.org/3/library/decimal.html).
    */
   export interface Schema$Decimal {
     /**