Updated build to run on older docker versions

Dockerfile

 FROM openjdk:8-jdk
 
-ENV ANDROID_COMPILE_SDK 27
-ENV ANDROID_BUILD_TOOLS 27.0.3
-ENV ANDROID_SDK_TOOLS 26.1.1
-
 RUN apt-get --quiet update --yes && \
     apt-get --quiet install --yes wget tar unzip lib32stdc++6 lib32z1
 RUN wget --quiet --output-document=android-sdk.zip https://dl.google.com/android/repository/sdk-tools-linux-3859397.zip && \
-    unzip -q android-sdk.zip -d android-sdk-linux
+    unzip -q android-sdk.zip -d android-sdk-linux && \
+    rm android-sdk.zip
 RUN mkdir android-sdk-linux/licenses && \
     printf "8933bad161af4178b1185d1a37fbf41ea5269c55\nd56f5187479451eabf01fb78af6dfcb131a6481e" > android-sdk-linux/licenses/android-sdk-license && \
     printf "84831b9409646a918e30573bab4c9c91346d8abd" > android-sdk-linux/licenses/android-sdk-preview-license
-RUn android-sdk-linux/tools/bin/sdkmanager --update > update.log
-RUN android-sdk-linux/tools/bin/sdkmanager "platforms;android-${ANDROID_COMPILE_SDK}" "build-tools;${ANDROID_BUILD_TOOLS}" "extras;google;m2repository" "extras;android;m2repository" > installPlatform.log
+RUN android-sdk-linux/tools/bin/sdkmanager --update > update.log
+RUN android-sdk-linux/tools/bin/sdkmanager \
+        "platforms;android-27" \
+        "build-tools;27.0.3" \
+        "extras;google;m2repository" \
+        "extras;android;m2repository" \
+    > installPlatform.log