Improve logging in Android apps

1. Redirect Android stdout/stderr to Android log ([how to](https://github.com/chaquo/chaquopy/blob/master/product/runtime/src/main/c/android_platform.c)).
2. Redirect Python stdout/stderr to Android log ([how to](https://github.com/chaquo/chaquopy/blob/master/product/runtime/src/main/python/java/android/__init__.py)).

Guide to JNI: https://www.baeldung.com/jni