Add android build to merge request

.gitlab-ci.yml

@@ -21,9 +21,12 @@ build-backend:
     - if: $CI_MERGE_REQUEST_ID
 
 build-android:
-  image: debian
+  image: docker:latest
   stage: build
+  services:
+    - docker:dind
   script: 
-    - echo "To be done"
+    - cd android
+    - docker build --pull -t android .
   rules:
     - if: $CI_MERGE_REQUEST_ID

android/Dockerfile

@@ -0,0 +1,29 @@
+FROM gradle:jdk8
+USER root
+
+ENV SDK_URL="https://dl.google.com/android/repository/commandlinetools-linux-6200805_latest.zip" \
+    ANDROID_HOME="/usr/local/android-sdk" \
+    ANDROID_VERSION=29 \
+    ANDROID_BUILD_TOOLS_VERSION=29.0.3
+	
+# Download Android SDK
+RUN mkdir "$ANDROID_HOME" .android && cd "$ANDROID_HOME" \
+    && curl -o sdk.zip $SDK_URL && unzip sdk.zip && rm sdk.zip \
+    && mkdir "$ANDROID_HOME/licenses" || true \
+    && echo "24333f8a63b6825ea9c5514f83c2829b004d1fee" > "$ANDROID_HOME/licenses/android-sdk-license"
+#    && yes | $ANDROID_HOME/tools/bin/sdkmanager --licenses
+
+# Install Android Build Tool and Libraries
+RUN $ANDROID_HOME/tools/bin/sdkmanager --sdk_root=$ANDROID_HOME "tools" > /dev/null
+RUN $ANDROID_HOME/tools/bin/sdkmanager --update > /dev/null
+RUN $ANDROID_HOME/tools/bin/sdkmanager "build-tools;${ANDROID_BUILD_TOOLS_VERSION}" "platforms;android-${ANDROID_VERSION}" "platform-tools" > /dev/null
+
+# Install Build Essentials
+RUN apt-get update \
+	&& apt-get install build-essential -y \
+	&& apt-get install file -y \
+	&& apt-get install apt-utils -y
+
+COPY . .
+
+RUN gradle assembleDebug