feat: audio support m4a

--story=1017864 --user=王孝刚 【应用】上传音频文件类型中支持m4a类型 #2276 https://www.tapd.cn/57709429/s/1654257

Author: wxg0103

ui/src/components/ai-chat/component/chat-input-operate/index.vue

@@ -260,7 +260,7 @@ const localLoading = computed({
 const imageExtensions = ['jpg', 'jpeg', 'png', 'gif', 'bmp']
 const documentExtensions = ['pdf', 'docx', 'txt', 'xls', 'xlsx', 'md', 'html', 'csv']
 const videoExtensions = ['mp4', 'avi', 'mov', 'mkv', 'flv']
-const audioExtensions = ['mp3', 'wav', 'ogg', 'aac']
+const audioExtensions = ['mp3', 'wav', 'ogg', 'aac', 'm4a']
 
 const getAcceptList = () => {
   const { image, document, audio, video } = props.applicationDetails.file_upload_setting