support mod_google_tts_streaming (#1409)

* support mod_google_tts_streaming

* wip

* wip

lib/utils/tts-streaming-buffer.js

@@ -421,6 +421,7 @@ class TtsStreamingBuffer extends Emitter {
       'cartesia',
       'elevenlabs',
       'rimelabs',
+      'google',
       'custom'
     ].forEach((vendor) => {
       const eventClassName = `${vendor.charAt(0).toUpperCase() + vendor.slice(1)}TtsStreamingEvents`;