Add JAVA_HOME (#97)

Author: safaiyeh

Dockerfile

@@ -19,6 +19,7 @@ ENV ANDROID_HOME=/opt/android
 ENV ANDROID_SDK_HOME=${ANDROID_HOME}
 ENV ANDROID_NDK=${ANDROID_HOME}/ndk/$NDK_VERSION
 ENV ANDROID_NDK_HOME=${ANDROID_HOME}/ndk/$NDK_VERSION
+ENV JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64
 
 ENV PATH=${ANDROID_NDK}:${ANDROID_HOME}/cmdline-tools/tools/bin:${ANDROID_HOME}/emulator:${ANDROID_HOME}/platform-tools:${ANDROID_HOME}/tools:${ANDROID_HOME}/tools/bin:/opt/buck/bin/:${PATH}