Android: Fix generate_gradle.py

build/android/gradle/android.jinja

 {# Copyright 2016 The Chromium Authors. All rights reserved. #}
 {# Use of this source code is governed by a BSD-style license that can be #}
 {# found in the LICENSE file. #}
 {% macro expand_sourceset(variables, prefix) %}
 {% if variables is defined %}
         {{ prefix }} {
 {% if variables.android_manifest is defined %}
             manifest.srcFile "{{ variables.android_manifest }}"
 {% endif %}
 {% if variables.java_dirs is defined %}
             java.srcDirs = [
 {% for path in variables.java_dirs %}
                 "{{ path }}",
 {% endfor %}
             ]
 {% endif %}
 {% if variables.java_excludes is defined %}
             java.filter.exclude(
 {% for path in variables.java_excludes %}
                 "{{ path }}",
 {% endfor %}
             )
 {% endif %}
-{% if variables.jniLibs is defined %}
+{% if variables.jni_libs is defined %}
             jniLibs.srcDirs = [
 {% for path in variables.jni_libs %}
                 "{{ path }}",
 {% endfor %}
             ]
 {% endif %}
 {% if variables.res_dirs is defined %}
             res.srcDirs = [
 {% for path in variables.res_dirs %}
                 "{{ path }}",
@@ skipping 66 matching lines @@
     }
     tasksToDisable.each { Task task ->
       task.enabled = false
     }
 {% if bootclasspath is defined %}
     tasks.withType(JavaCompile) {
       options.bootClasspath = "{{ bootclasspath }}"
     }
 {% endif %}
 }