Audio fix, hint for signal 9, mount font folder

1、修复了音频，现在可以播放声音了；
2、加入了出现“signal 9”错误的提示信息；
3、软件在拥有存储访问权限的情况下，会自动在手机端wps，永中office的外部字体文件夹(AppFiles/Fonts，Fonts)查找字体文件(即挂载这两个目录)，这样就可以不用单独为容器里的wps导入字体了。

pubspec.yaml

@@ -16,7 +16,7 @@ publish_to: 'none' # Remove this line if you wish to publish to pub.dev
 # https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
 # In Windows, build-name is used as the major, minor, and patch parts
 # of the product and file versions while build-number is used as the build suffix.
-version: 1.0.0+1
+version: 1.0.1+1
 
 environment:
   sdk: '>=3.1.0 <4.0.0'
@@ -38,6 +38,7 @@ dependencies:
   http: ^1.1.0
   retry: ^3.1.2
   url_launcher: ^6.1.12
+  device_info_plus: ^9.0.3
 
 
   # The following adds the Cupertino Icons font to your application.