Use Android SDK Manager to install NDK and CMake on travis

.travis.yml

@@ -29,7 +29,7 @@ matrix:
               sources: [ 'kubuntu-backports', 'george-edison55-precise-backports' ]
               packages: [ 'cmake', 'lib32z1-dev', 'lib32stdc++6', 's3cmd' ]
           android:
-            components: [ 'tools', 'build-tools-24.0.2', 'extra-android-m2repository', 'android-25', 'ndk-bundle', 'cmake' ]
+            components: [ 'tools', 'build-tools-24.0.2', 'extra-android-m2repository', 'android-25', 'ndk-bundle', 'cmake-3.6.3155560' ]
           jdk: oraclejdk8
 
 before_install:

scripts/travis/before_install.sh

@@ -3,42 +3,6 @@
 set -e
 set -o pipefail
 
-if [[ ${PLATFORM} == "android" ]]; then
-
-    # Note: the right way to download these packages is through the Android Studio SDK manager,
-    # these steps should be removed when/if ndk-bundle and cmake become available from the
-    # command-line SDK update tool.
-
-    # Download android ndk
-    echo "Downloading ndk..."
-    curl -L https://dl.google.com/android/repository/android-ndk-r13b-linux-x86_64.zip -o ndk.zip
-    echo "Done."
-
-    # Extract android ndk
-    echo "Extracting ndk..."
-    unzip -qq ndk.zip
-    echo "Done."
-
-    # Update PATH
-    echo "Updating PATH..."
-    export ANDROID_NDK_HOME=${PWD}/android-ndk-r13b
-    export PATH=${PATH}:${ANDROID_HOME}/tools:${ANDROID_NDK_HOME}
-    echo $PATH
-    echo "Done."
-
-    # Download android cmake package
-    echo "Downloading android cmake package..."
-    curl -L https://dl.google.com/android/repository/cmake-3.6.3155560-linux-x86_64.zip -o cmake.zip
-    echo "Done."
-
-    # Extract android cmake package
-    echo "Extracting android cmake package..."
-    mkdir -p ${ANDROID_HOME}/cmake
-    unzip -qq cmake.zip -d ${ANDROID_HOME}/cmake
-    echo "Done."
-
-fi
-
 if [[ ${TRAVIS_OS_NAME} == "osx" ]]; then
 
     # https://github.com/travis-ci/travis-ci/issues/6307