feat: update v1beta1 proto (#562)

* feat: update v1beta1 proto

PiperOrigin-RevId: 409139454

Source-Link: googleapis/googleapis@7c10623

Source-Link: https://github.com/googleapis/googleapis-gen/commit/48051ebabf991abcddcb2685cefc331aea7f5208
Copy-Tag: eyJwIjoiLmdpdGh1Yi8uT3dsQm90LnlhbWwiLCJoIjoiNDgwNTFlYmFiZjk5MWFiY2RkY2IyNjg1Y2VmYzMzMWFlYTdmNTIwOCJ9

* 🦉 Updates from OwlBot

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

protos/google/cloud/texttospeech/v1beta1/cloud_tts.proto

@@ -19,6 +19,7 @@ package google.cloud.texttospeech.v1beta1;
 import "google/api/annotations.proto";
 import "google/api/client.proto";
 import "google/api/field_behavior.proto";
+import "google/api/resource.proto";
 
 option cc_enable_arenas = true;
 option csharp_namespace = "Google.Cloud.TextToSpeech.V1Beta1";
@@ -28,6 +29,10 @@ option java_outer_classname = "TextToSpeechProto";
 option java_package = "com.google.cloud.texttospeech.v1beta1";
 option php_namespace = "Google\\Cloud\\TextToSpeech\\V1beta1";
 option ruby_package = "Google::Cloud::TextToSpeech::V1beta1";
+option (google.api.resource_definition) = {
+  type: "automl.googleapis.com/Model"
+  pattern: "projects/{project}/locations/{location}/models/{model}"
+};
 
 // Service that implements Google Cloud Text-to-Speech API.
 service TextToSpeech {
@@ -59,11 +64,11 @@ message ListVoicesRequest {
   // [BCP-47](https://www.rfc-editor.org/rfc/bcp/bcp47.txt) language tag.
   // If not specified, the API will return all supported voices.
   // If specified, the ListVoices call will only return voices that can be used
-  // to synthesize this language_code. E.g. when specifying "en-NZ", you will
-  // get supported "en-NZ" voices; when specifying "no", you will get supported
-  // "no-\*" (Norwegian) and "nb-\*" (Norwegian Bokmal) voices; specifying "zh"
-  // will also get supported "cmn-\*" voices; specifying "zh-hk" will also get
-  // supported "yue-hk" voices.
+  // to synthesize this language_code. E.g. when specifying `"en-NZ"`, you will
+  // get supported `"en-NZ"` voices; when specifying `"no"`, you will get
+  // supported `"no-\*"` (Norwegian) and `"nb-\*"` (Norwegian Bokmal) voices;
+  // specifying `"zh"` will also get supported `"cmn-\*"` voices; specifying
+  // `"zh-hk"` will also get supported `"yue-hk"` voices.
   string language_code = 1 [(google.api.field_behavior) = OPTIONAL];
 }
 
@@ -208,6 +213,11 @@ message VoiceSelectionParams {
   // voice of the appropriate gender is not available, the synthesizer should
   // substitute a voice with a different gender rather than failing the request.
   SsmlVoiceGender ssml_gender = 3;
+
+  // The configuration for a custom voice. If [CustomVoiceParams.model] is set,
+  // the service will choose the custom voice matching the specified
+  // configuration.
+  CustomVoiceParams custom_voice = 4;
 }
 
 // Description of audio data to be synthesized.
@@ -266,6 +276,37 @@ message AudioConfig {
   ];
 }
 
+// Description of the custom voice to be synthesized.
+message CustomVoiceParams {
+  // The usage of the synthesized audio. You must report your honest and
+  // correct usage of the service as it's regulated by contract and will cause
+  // significant difference in billing.
+  enum ReportedUsage {
+    // Request with reported usage unspecified will be rejected.
+    REPORTED_USAGE_UNSPECIFIED = 0;
+
+    // For scenarios where the synthesized audio is not downloadable and can
+    // only be used once. For example, real-time request in IVR system.
+    REALTIME = 1;
+
+    // For scenarios where the synthesized audio is downloadable and can be
+    // reused. For example, the synthesized audio is downloaded, stored in
+    // customer service system and played repeatedly.
+    OFFLINE = 2;
+  }
+
+  // Required. The name of the AutoML model that synthesizes the custom voice.
+  string model = 1 [
+    (google.api.field_behavior) = REQUIRED,
+    (google.api.resource_reference) = {
+      type: "automl.googleapis.com/Model"
+    }
+  ];
+
+  // Optional. The usage of the synthesized audio to be reported.
+  ReportedUsage reported_usage = 3 [(google.api.field_behavior) = OPTIONAL];
+}
+
 // The message returned to the client by the `SynthesizeSpeech` method.
 message SynthesizeSpeechResponse {
   // The audio data bytes encoded as specified in the request, including the