feat: [Speech] add custom prompt config in the request and return prompt in the response (#8851)

feat: add custom prompt config in the request and return prompt in the response
feat: update min_speaker_count and max_speaker_count to be optional
docs: Clarify that min_speaker_count and max_speaker_count in SpeakerDiarizationConfig are not currently used
docs: Update guidance on how to enable speaker diarization; to enable, set the diarization_config field to an empty SpeakerDiarizationConfig message

PiperOrigin-RevId: 852383212

Source-Link: googleapis/googleapis@1a14153

Source-Link: googleapis/googleapis-gen@c84243c

Author: bshaffer

Speech/metadata/V2/CloudSpeech.php

@@ -133,9 +133,7 @@ final class SpeechClient
     private const CODEGEN_NAME = 'gapic';
 
     /** The default scopes required by the service. */
-    public static $serviceScopes = [
-        'https://www.googleapis.com/auth/cloud-platform',
-    ];
+    public static $serviceScopes = ['https://www.googleapis.com/auth/cloud-platform'];
 
     private $operationsClient;
 
@@ -256,8 +254,13 @@ public static function cryptoKeyName(string $project, string $location, string $
      *
      * @return string The formatted crypto_key_version resource.
      */
-    public static function cryptoKeyVersionName(string $project, string $location, string $keyRing, string $cryptoKey, string $cryptoKeyVersion): string
-    {
+    public static function cryptoKeyVersionName(
+        string $project,
+        string $location,
+        string $keyRing,
+        string $cryptoKey,
+        string $cryptoKeyVersion
+    ): string {
         return self::getPathTemplate('cryptoKeyVersion')->render([
             'project' => $project,
             'location' => $location,