The unaligned apk is just an intermediate apk. First, the unaligned apk is generated. Then, the unaligned apk gets aligned and produces the aligned apk which is the app-debug.apk. 

实际上分为两个过程,这个unaligend仅仅是个中间产物(intermediate product). 
- 1.生成unaligned APK. 
- 2.unaligned APK变为aligned,并且产生app-debug.apk.