[DOC] Add Android Tutorial (#2977)

* fix APP_STL for latest android ndk

* add vulkan sdk for tutorial

* add android tutorial

* fix of invalid input layer name

* update relay build opt_level 1 -> 3

apps/android_rpc/app/src/main/jni/Application.mk

@@ -12,7 +12,7 @@ include $(config)
 # 1) armeabi is deprecated in NDK r16 and removed in r17
 # 2) vulkan is not supported in armeabi
 APP_ABI ?= armeabi-v7a arm64-v8a x86 x86_64 mips
-APP_STL := c++_static
+APP_STL := c++_shared
 
 APP_CPPFLAGS += -DDMLC_LOG_STACK_TRACE=0 -DTVM4J_ANDROID=1 -std=c++11 -Oz -frtti
 ifeq ($(USE_OPENCL), 1)

docker/Dockerfile.demo_android

@@ -44,9 +44,28 @@ RUN bash /install/ubuntu_install_gradle.sh
 COPY install/ubuntu_install_androidsdk.sh /install/ubuntu_install_androidsdk.sh
 RUN bash /install/ubuntu_install_androidsdk.sh
 
+COPY install/ubuntu_install_vulkan.sh /install/ubuntu_install_vulkan.sh
+RUN bash /install/ubuntu_install_vulkan.sh
+
+ENV VULKAN_SDK /usr/local/VulkanSDK/1.0.65.0/x86_64
+ENV PATH ${PATH}:${VULKAN_SDK}/bin
+ENV LD_LIBRARY_PATH ${LD_LIBRARY_PATH}:${VULKAN_SDK}/lib
+ENV VK_LAYER_PATH ${VULKAN_SDK}/etc/explicit_layer.d
+
 # Build TVM
-COPY install/install_tvm_cpu.sh /install/install_tvm_cpu.sh
-RUN bash /install/install_tvm_cpu.sh
+RUN cd /usr && \
+    git clone --depth=1 https://github.com/dmlc/tvm --recursive && \
+    cd /usr/tvm && \
+    mkdir -p build && \
+    cd build && \
+    cmake \
+        -DUSE_LLVM=llvm-config-6.0 \
+        -DUSE_RPC=ON \
+        -DUSE_SORT=ON \
+        -DUSE_GRAPH_RUNTIME=ON \
+        -DUSE_VULKAN=ON \
+        .. && \
+    make -j10
 
 # Environment variables
 ENV PYTHONPATH=/usr/tvm/python:/usr/tvm/topi/python:/usr/tvm/nnvm/python/:/usr/tvm/vta/python:${PYTHONPATH}