[demo-express] Show file content automatically for FileReader
[demo-express] Show file content automatically for FileReader

Impacted tests(approved):new 0,update 1,delete 0
Unit test platform:[Android]
Unit test result summary:pass 1,fail 0,block 0

haoxli/demo-express,zhuyongyong/demo-express,wanghongjuan/demo-express,axinging/demo-express,haoxli/demo-express,chunywang/demo-express,axinging/demo-express,wanghongjuan/demo-express,axinging/demo-express,chunywang/demo-express,wanghongjuan/demo-express,yunxliu/demo-express,kangxu/demo-express,chunywang/demo-express,yunxliu/demo-express,kangxu/demo-express,axinging/demo-express,kangxu/demo-express,zhuyongyong/demo-express,yunxliu/demo-express,haoxli/demo-express,kangxu/demo-express,yunxliu/demo-express,haoxli/demo-express,zhuyongyong/demo-express,zhuyongyong/demo-express,chunywang/demo-express,wanghongjuan/demo-express