The package compressing reduced the obb file size to about 1/3. From 37MB to 12.MB. The total size APK + OBB is 35MB now(ETC1). The ASTC has the same size as ETC1 after compressed. It is also total 35MB size.
But the Program APK is still very large.
The most part of it is libUE4.so. It is about 20MB even after apk compressed (61.2MB uncompressed). It occupates nearly 85% size of total APK.