README: Update with Android instructions

Signed-off-by: Patrick José Pereira <[email protected]>

README.md

@@ -1,4 +1,15 @@
- cmake ../AtCore-Gui \
+# AtCore-Gui
+
+export ANDROID_NDK=/opt/android-ndk/
+# note the _ROOT postfix here, different pattern
+export ANDROID_SDK_ROOT=/opt/android-sdk/
+export Qt5_android=/opt/android-qt5/5.9.1/armeabi/
+export PATH=/opt/android-sdk/platform-tools/:$PATH
+# adapt the following path to your ant installation
+export ANT=/usr/bin/ant
+export JAVA_HOME=/usr/lib/jvm/java-8-openjdk/
+
+cmake ../AtCore-Gui \
     -DCMAKE_TOOLCHAIN_FILE=/usr/share/ECM/toolchain/Android.cmake \
     -DECM_ADDITIONAL_FIND_ROOT_PATH=/opt/android-qt5/5.9.1/armeabi/ \
     -DCMAKE_MODULE_PATH=/opt/android-qt5/5.9.1/armeabi/lib/cmake/ \
@@ -10,6 +21,7 @@
     -DQt5Core_DIR=/opt/android-qt5/5.9.1/armeabi/lib/cmake/Qt5Core/ \
     -DQTANDROID_EXPORTED_TARGET=atcore-gui -DANDROID_APK_DIR=/home/patrick/git/patrick/AtCore-Gui/
 
-
 make create-apk-atcore-gui
 
+./atcore-gui_build_apk/build/outputs/apk/atcore-gui_build_apk-debug.apk
+