[ag] Update dockerfile to match config in passing local build

* PROBLEM: the build fails on gitlab in a debian-based docker container
* BUT: i (@aguestuser) have a recently-achieved passing build on a
  debian laptop
* ATTEMPTED SOLUTION: construct a dockerfile that matches my local
  configuration as precisely as possible
* PROGRESS: the build gets further than it did before -- getting part of
  the way through the `buildNative` gradle script before failing
* REMAINING FAILURE: several arm64 cross-compile steps in the
  `ndk-build` step fail because they depend on
  [neon](https://developer.android.com/ndk/guides/cpu-arm-neon.html):

```shell
[arm64-v8a] Compile        : crypto_static <= aesv8-armx-64.S
openssl/crypto/aes/asm/aesv8-armx-64.S:35:2: error: instruction requires: neon
 eor v0.16b,v0.16b,v0.16b
 ^
openssl/crypto/aes/asm/aesv8-armx-64.S:36:2: error: instruction requires: neon
 ld1 {v3.16b},[x0],#16
 ^
openssl/crypto/aes/asm/aesv8-armx-64.S:38:2: error: instruction requires: neon
 ld1 {v1.4s,v2.4s},[x3],#32
```

* PROPOSED NEXT STEPS:
  * consult team to see if there's any collective wisdom about `neon`
  * look for ways to analyze diff of c dependencies in local machine
    v. docker instance
  * consider using ubuntu or debian:sid as the base image for the
    android container?

2 files changed, 93 insertions, 2 deletions

diff --git a/app/build.gradle b/app/build.gradle
index cd7e6e21..b6bb39ff 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -2,8 +2,8 @@ apply plugin: 'com.android.application'
 
 android {
   compileSdkVersion 23
-  buildToolsVersion '25.0.0'
-
+  buildToolsVersion '25.0.2'
+;
   signingConfigs {
     release {
       storeFile project.hasProperty('storeFileProperty') ? file(storeFileProperty) : null
diff --git a/docker/android-sdk.dockerfile b/docker/android-sdk.dockerfile
new file mode 100644
index 00000000..dddf54c6
--- /dev/null
+++ b/docker/android-sdk.dockerfile
@@ -0,0 +1,91 @@
+FROM debian:stretch
+
+MAINTAINER LEAP Encryption Access Project <info@leap.se>
+LABEL Description="Android SDK baseimage based on debian:stretch" Vendor="LEAP" Version="0.0.1"
+
+# ------------------------------------------------------
+# --- Install System Dependencies
+
+# Update Debian
+RUN apt-get update -qq
+
+# Install Debian Packages
+RUN DEBIAN_FRONTEND=noninteractive apt-get install -y \
+  # the basics
+  wget unzip git locales \
+  # java stuff
+  openjdk-8-jdk maven \ 
+  # c libraries
+  make clang lib32stdc++6 lib32z1 # (incl. 32-bit compatible versions)
+
+# libgcc-6-dev-arm64-cross
+
+# Set Locale
+RUN locale-gen en_US.UTF-8  
+RUN localedef -i en_US -c -f UTF-8 -A /usr/share/locale/locale.alias en_US.UTF-8
+
+# ------------------------------------------------------
+# --- Install Android SDK Tools
+
+ENV ANDROID_HOME /opt/android-sdk-linux
+ENV SDK_TOOLS_VERSION "25.2.5"
+
+# Install SDK Tools
+RUN cd /opt \
+    && wget -q -O sdk-tools.zip \
+    https://dl.google.com/android/repository/tools_r${SDK_TOOLS_VERSION}-linux.zip \
+    && unzip -q sdk-tools.zip -d ${ANDROID_HOME} \
+    && rm -f sdk-tools.zip
+
+# Update PATH
+ENV PATH ${PATH}:${ANDROID_HOME}/tools:${ANDROID_HOME}/tools/bin:${ANDROID_HOME}/platform-tools
+
+# Install Platform Tools Package
+RUN echo y | sdkmanager "platform-tools" # echo y to accept google licenses
+
+# Install Android Support Repositories
+RUN echo y | sdkmanager "extras;android;m2repository"
+
+# Install Target SDK Packages (Please keep in descending order)
+RUN echo y | sdkmanager "platforms;android-25"
+RUN echo y | sdkmanager "platforms;android-24"
+RUN echo y | sdkmanager "platforms;android-23"
+
+# Install Build Tools (Please keep in descending order)
+RUN echo y | sdkmanager "build-tools;25.0.2"
+RUN echo y | sdkmanager "build-tools;24.0.3"
+RUN echo y | sdkmanager "build-tools;23.0.3"
+
+# ------------------------------------------------------
+# --- Install Android NDK (for running C code)
+
+ENV ANDROID_NDK_HOME ${ANDROID_HOME}/ndk-bundle
+
+# Install NDK packages from sdk tools
+
+RUN echo y | sdkmanager "ndk-bundle"
+RUN echo y | sdkmanager "cmake;3.6.3155560"
+RUN echo y | sdkmanager "lldb;2.3"
+
+# Update PATH
+
+ENV PATH ${PATH}:${ANDROID_NDK_HOME}
+
+
+# ------------------------------------------------------
+# --- Install Android Emulator
+
+
+# RUN echo y | sdkmanager "emulator"
+
+# System Images for emulators
+# RUN echo y | sdkmanager "system-images;android-25;google_apis;armeabi-v7a"
+# RUN echo y | sdkmanager "system-images;android-24;google_apis;armeabi-v7a"
+# RUN echo y | sdkmanager "system-images;android-23;google_apis;armeabi-v7a"
+# RUN echo y | sdkmanager "system-images;android-23;google_apis;arm64-v8a"
+
+# ------------------------------------------------------
+# --- Cleanup
+
+RUN apt-get clean
+