我发现了问题所在. 旧的opencv库(存在漏洞问题)创建了 libopencv_java.so 文件，并且仍在 libs 中>文件夹，即使更新了库也是如此.因此，新的 .so 文件无法生成.

I found out the problem. The old opencv library(which has vulnerability issue) created libopencv_java.so file and it was still there in the libs folder even after updating the library. So somehow the new .so file was not generating.

已采取步骤解决:

• 首先我从libs文件夹中删除了 libopencv_java.so .
• 为清楚起见，我删除了 build 文件夹中的所有内容.
• 添加了opencv 2.4.13.1 gradle依赖项(编译'com.iparse.android:opencv:2.4.13.1')

• First i deleted libopencv_java.so from libs folder.
• Just for clarity, i deleted everything which was there in the build folder.
• Added opencv 2.4.13.1 gradle dependency (compile 'com.iparse.android:opencv:2.4.13.1')

如果要检查opencv使用的libpng版本，请首先找到 libopencv_java.so ，该文件位于 libs 或 build 文件夹中，在终端strings libopencv_java.so | grep "libpng"中使用以下命令.

If you want to check the libpng version used by opencv, first find libopencv_java.so which will be in libs or build folder and use the following command in terminal strings libopencv_java.so | grep "libpng".

此后，我在playstore中发布了，一切都很好.希望这对某人有帮助.

After this i published in playstore and everything is fine. Hope this helps someone.