Integrate QNN backend to LlamaDemo (#3346)

Summary:
repro:

(specify `QNN_SDK_ROOT` first)

```
pushd examples/demo-apps/android/LlamaDemo
./gradlew :app:setupQnn
./gradlew :app:installDebug
```

Pull Request resolved: #3346

Reviewed By: cccclai

Differential Revision: D56556854

Pulled By: kirklandsign

fbshipit-source-id: 38ec067c29634e7b13ec3512c713b4dfe50ed739

Author: kirklandsign

examples/demo-apps/android/LlamaDemo/app/build.gradle.kts

@@ -76,3 +76,12 @@ tasks.register("setup") {
     }
   }
 }
+
+tasks.register("setupQnn") {
+  doFirst {
+    exec {
+      commandLine("sh", "examples/demo-apps/android/LlamaDemo/setup-with-qnn.sh")
+      workingDir("../../../../../")
+    }
+  }
+}

examples/demo-apps/android/LlamaDemo/app/src/main/AndroidManifest.xml

@@ -21,7 +21,7 @@
         android:extractNativeLibs="true"
         tools:targetApi="34">
 
-        <uses-native-library android:name="libexecutorch.so"
+        <uses-native-library android:name="libcdsprpc.so"
             android:required="false"/>
 
         <activity

examples/demo-apps/android/LlamaDemo/app/src/main/java/com/example/executorchllamademo/MainActivity.java

@@ -13,6 +13,8 @@
 import android.app.AlertDialog;
 import android.content.Context;
 import android.os.Bundle;
+import android.system.ErrnoException;
+import android.system.Os;
 import android.widget.Button;
 import android.widget.EditText;
 import android.widget.ImageButton;
@@ -161,6 +163,12 @@ protected void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
     setContentView(R.layout.activity_main);
 
+    try {
+      Os.setenv("ADSP_LIBRARY_PATH", getApplicationInfo().nativeLibraryDir, true);
+    } catch (ErrnoException e) {
+      finish();
+    }
+
     mEditTextMessage = findViewById(R.id.editTextMessage);
     mSendButton = findViewById(R.id.sendButton);
     mSendButton.setEnabled(false);

examples/demo-apps/android/LlamaDemo/setup-with-qnn.sh

@@ -0,0 +1,61 @@
+#!/usr/bin/env bash
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the BSD-style license found in the
+# LICENSE file in the root directory of this source tree.
+
+set -eu
+
+CMAKE_OUT="${CMAKE_OUT:-cmake-out-android}"
+# Note: Set up ANDROID_NDK and ANDROID_ABI
+cmake . -DCMAKE_INSTALL_PREFIX="${CMAKE_OUT}" \
+  -DCMAKE_TOOLCHAIN_FILE="${ANDROID_NDK}/build/cmake/android.toolchain.cmake" \
+  -DANDROID_ABI="${ANDROID_ABI}" \
+  -DEXECUTORCH_BUILD_XNNPACK=ON \
+  -DEXECUTORCH_BUILD_EXTENSION_DATA_LOADER=ON \
+  -DEXECUTORCH_BUILD_EXTENSION_MODULE=ON \
+  -DEXECUTORCH_BUILD_OPTIMIZED=ON \
+  -DEXECUTORCH_BUILD_QNN=ON \
+  -DQNN_SDK_ROOT="${QNN_SDK_ROOT}" \
+  -DCMAKE_BUILD_TYPE=Release \
+  -B"${CMAKE_OUT}"
+
+if [ "$(uname)" == "Darwin" ]; then
+  CMAKE_JOBS=$(( $(sysctl -n hw.ncpu) - 1 ))
+else
+  CMAKE_JOBS=$(( $(nproc) - 1 ))
+fi
+cmake --build "${CMAKE_OUT}" -j "${CMAKE_JOBS}" --target install --config Release
+
+cmake examples/models/llama2 \
+         -DCMAKE_TOOLCHAIN_FILE=$ANDROID_NDK/build/cmake/android.toolchain.cmake \
+         -DANDROID_ABI="$ANDROID_ABI" \
+         -DCMAKE_INSTALL_PREFIX="${CMAKE_OUT}" \
+         -DCMAKE_BUILD_TYPE=Release \
+         -B"${CMAKE_OUT}"/examples/models/llama2
+
+cmake --build "${CMAKE_OUT}"/examples/models/llama2 -j "${CMAKE_JOBS}" --config Release
+
+cmake extension/android \
+  -DCMAKE_TOOLCHAIN_FILE=${ANDROID_NDK}/build/cmake/android.toolchain.cmake \
+  -DANDROID_ABI="${ANDROID_ABI}" \
+  -DCMAKE_INSTALL_PREFIX="${CMAKE_OUT}" \
+  -DEXECUTORCH_BUILD_LLAMA_JNI=ON \
+  -DCMAKE_BUILD_TYPE=Release \
+  -B"${CMAKE_OUT}"/extension/android
+
+cmake --build "${CMAKE_OUT}"/extension/android -j "${CMAKE_JOBS}" --config Release
+
+JNI_LIBS_PATH="examples/demo-apps/android/LlamaDemo/app/src/main/jniLibs"
+mkdir -p "${JNI_LIBS_PATH}/${ANDROID_ABI}"
+cp "${CMAKE_OUT}"/extension/android/libexecutorch_llama_jni.so "${JNI_LIBS_PATH}/${ANDROID_ABI}/"
+cp "${CMAKE_OUT}"/lib/libqnn_executorch_backend.so "${JNI_LIBS_PATH}/${ANDROID_ABI}/"
+cp "${QNN_SDK_ROOT}"/lib/aarch64-android/libQnnHtp.so "${JNI_LIBS_PATH}/${ANDROID_ABI}/"
+cp "${QNN_SDK_ROOT}"/lib/aarch64-android/libQnnSystem.so "${JNI_LIBS_PATH}/${ANDROID_ABI}/"
+cp "${QNN_SDK_ROOT}"/lib/aarch64-android/libQnnHtpV69Stub.so "${JNI_LIBS_PATH}/${ANDROID_ABI}/"
+cp "${QNN_SDK_ROOT}"/lib/aarch64-android/libQnnHtpV73Stub.so "${JNI_LIBS_PATH}/${ANDROID_ABI}/"
+cp "${QNN_SDK_ROOT}"/lib/aarch64-android/libQnnHtpV75Stub.so "${JNI_LIBS_PATH}/${ANDROID_ABI}/"
+cp "${QNN_SDK_ROOT}"/lib/hexagon-v69/unsigned/libQnnHtpV69Skel.so "${JNI_LIBS_PATH}/${ANDROID_ABI}/"
+cp "${QNN_SDK_ROOT}"/lib/hexagon-v73/unsigned/libQnnHtpV73Skel.so "${JNI_LIBS_PATH}/${ANDROID_ABI}/"
+cp "${QNN_SDK_ROOT}"/lib/hexagon-v75/unsigned/libQnnHtpV75Skel.so "${JNI_LIBS_PATH}/${ANDROID_ABI}/"