title: NDK, CMake, and Android in TravisCI
body: <p>I'm trying to set up my CI for a Android project that uses some C++ code. As such I need the NDK that doesn't come pre-installed on Travis Android images.  I'm currently achieving this by pulling the NDK myself, however my CI box is complaining about the CMake license not being accepted. The weird thing is that I thought this was included in the android-sdk-license which I am already including in my build.  My travis YAML looks like this:</p>
  
  <pre><code>language: android
  
  jdk:
    - oraclejdk8
    - oraclejdk9
  
  android:
    components:
      - tools
      - platform-tools
      - tools
      - build-tools-26.0.2
      - android-26
      - extra-android-m2repository
      - extra-google-m2repository
      - extra-android-support
      - extra-google-google_play_services
      - add-on
      - extra
  
  licenses:
    - 'android-sdk-preview-license-.+'
    - 'android-sdk-license-.+'
  
  before_script:
    - wget https://dl.google.com/android/repository/android-ndk-r16b-linux-x86_64.zip
    - unzip -qq android-ndk-r16b-linux-x86_64.zip
    - export ANDROID_NDK_HOME=`pwd`/android-ndk-r16b
    - export LOCAL_ANDROID_NDK_HOME="$ANDROID_NDK_HOME"
    - export LOCAL_ANDROID_NDK_HOST_PLATFORM="linux-x86_64"
    - export PATH=$PATH:${ANDROID_NDK_HOME}
    - env
  
  script: ./gradlew build jacocoTestReport
  
  matrix:
    fast_finish: true
    allow_failures:
      - jdk: oraclejdk9
  
  notifications:
    email: false
  
  after_success:
    — bash &lt;(curl -s https://codecov.io/bash)
  </code></pre>
  
  <p>The license error can be seen at the bottom of the build <a href="https://travis-ci.org/jhole89/tensorflow-classifier-android/jobs/315017502#L3264" rel="noreferrer">here</a></p>