gn2bp: Generate sources file for jni_registration_generator.py

Path in the original sources file does not work in the genrule.
So, generating sources file based on srcs and use this file from
jni_registration_generator.py

Test: ./update_results.sh
Change-Id: Ia1d56b55b441b969191c33ca25a7fff25c033035
2 files changed