It was causing an error:

ERROR at //brave/build/android/BUILD.gn:99:17: Assignment had no effect.
  jni_package = "brave"
                ^------
You set the variable "jni_package" here and it was unused before it went
out of scope.
See //brave/build/android/BUILD.gn:93:1: whence it was called.
generate_jni("jni_headers") {
^----------------------------
See //brave/BUILD.gn:55:11: which caused the file to be included.
  deps = ["build/$target_os:brave"]
          ^-----------------------