Add a script to build the server without gradle

Gradle versions may sometimes cause problems. This script offers an
alternative.

server/build_without_gradle.sh

@@ -0,0 +1,62 @@
+#!/bin/bash
+#
+# This script generates the scrcpy binary "manually" (without gradle).
+#
+# Adapt Android platform and build tools versions (via ANDROID_PLATFORM and
+# ANDROID_BUILD_TOOLS environment variables).
+#
+# Then execute:
+#
+#     BUILD_DIR=my_build_dir ./build_without_gradle.sh
+
+set -e
+
+PLATFORM=${ANDROID_PLATFORM:-29}
+BUILD_TOOLS=${ANDROID_BUILD_TOOLS:-29.0.2}
+
+BUILD_DIR="$(realpath ${BUILD_DIR:-build_manual})"
+CLASSES_DIR="$BUILD_DIR/classes"
+SERVER_DIR=$(dirname "$0")
+SERVER_BINARY=scrcpy-server.jar
+
+echo "Platform: android-$PLATFORM"
+echo "Build-tools: $BUILD_TOOLS"
+echo "Build dir: $BUILD_DIR"
+
+rm -rf "$CLASSES_DIR" "$BUILD_DIR/$SERVER_BINARY" classes.dex
+mkdir -p "$CLASSES_DIR/com/genymobile/scrcpy"
+
+<< EOF cat > "$CLASSES_DIR/com/genymobile/scrcpy/BuildConfig.java"
+package com.genymobile.scrcpy;
+
+public final class BuildConfig {
+  public static final boolean DEBUG = false;
+}
+EOF
+
+echo "Generating java from aidl..."
+cd "$SERVER_DIR/src/main/aidl"
+"$ANDROID_HOME/build-tools/$BUILD_TOOLS/aidl" -o "$CLASSES_DIR" \
+    android/view/IRotationWatcher.aidl
+
+echo "Compiling java sources..."
+cd ../java
+javac -bootclasspath "$ANDROID_HOME/platforms/android-$PLATFORM/android.jar" \
+    -cp "$CLASSES_DIR" -d "$CLASSES_DIR" -source 1.8 -target 1.8 \
+    com/genymobile/scrcpy/*.java \
+    com/genymobile/scrcpy/wrappers/*.java
+
+echo "Dexing..."
+cd "$CLASSES_DIR"
+"$ANDROID_HOME/build-tools/$BUILD_TOOLS/dx" --dex \
+    --output "$BUILD_DIR/classes.dex" \
+    android/view/*.class \
+    com/genymobile/scrcpy/*.class \
+    com/genymobile/scrcpy/wrappers/*.class
+
+echo "Archiving..."
+cd "$BUILD_DIR"
+jar cvf "$SERVER_BINARY" classes.dex
+rm -rf classes.dex classes
+
+echo "Server generated in $BUILD_DIR/scrcpy-server.jar"