Use this tool to setprop ro.debuggable 1 and you can debug your apk without change AndroidManifest.xml. Tool Author @ netsniffer More info: https://bbs.pediy.com/thread-215311.htm
Souce code:
./jni/mprop.c
Binary path
./obj/local/arm64-v8a/mprop
Just type the follwing command. If you see 1 in the end ,it means you succeeded.
make build
make run
# internals in Makefile.mk