Import jni_generator from root package am: 463ea434c7 am: 2232bd223f

Original change: https://android-review.googlesource.com/c/platform/external/libchrome/+/2237476

Change-Id: Ie57be2e3fbf51713cd528b25f517a4b25588e6ce
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>