build: Bundle jni-utils into droidplug.aar in build script

It's the way we've worked before, don't want to change it.

Author: qdot

scripts/build-java.sh

@@ -206,7 +206,7 @@ run_gradle_build() {
         chmod +x ./gradlew
     fi
 
-    ./gradlew assembleDebug "$@"
+    ./gradlew assembleDebug assembleRelease "$@"
 
     info "Java build completed successfully."
 }

src/droidplug/java/build.gradle

@@ -28,3 +28,49 @@ dependencies {
     implementation 'io.github.gedgygedgy.rust:jni-utils:0.1.1-SNAPSHOT'
     //implementation files('c:/Users/qdot/code/jni-utils-rs/java/build/libs/jni-utils-0.1.1-SNAPSHOT.jar')
 }
+
+// Embed jni-utils classes into the AAR's classes.jar so consumers that include
+// this AAR as a flat file (without Maven dependency resolution) get the
+// transitive dependency bundled automatically.
+android.libraryVariants.configureEach { variant ->
+    def name = variant.name.capitalize()
+    tasks.named("bundle${name}Aar").configure { bundleTask ->
+        bundleTask.doLast {
+            def aarFile = bundleTask.archiveFile.get().asFile
+            def tmpDir = new File(project.layout.buildDirectory.asFile.get(), "tmp/fataar-${variant.name}")
+            if (tmpDir.exists()) tmpDir.deleteDir()
+            tmpDir.mkdirs()
+
+            // Extract the AAR
+            ant.unzip(src: aarFile, dest: tmpDir)
+
+            // Collect runtime dependency JARs and merge into classes.jar
+            def classesJar = new File(tmpDir, "classes.jar")
+            def mergeDir = new File(tmpDir, "_merge")
+            mergeDir.mkdirs()
+
+            // Extract existing classes.jar
+            ant.unzip(src: classesJar, dest: mergeDir)
+
+            // Extract each runtime dependency JAR
+            configurations.getByName("${variant.name}RuntimeClasspath").files.each { jar ->
+                if (jar.name.endsWith(".jar")) {
+                    ant.unzip(src: jar, dest: mergeDir) {
+                        patternset { exclude(name: "META-INF/**") }
+                    }
+                }
+            }
+
+            // Re-jar
+            classesJar.delete()
+            ant.jar(destfile: classesJar, basedir: mergeDir)
+
+            // Cleanup merge dir before re-packaging
+            mergeDir.deleteDir()
+
+            // Re-package the AAR
+            aarFile.delete()
+            ant.zip(destfile: aarFile, basedir: tmpDir)
+        }
+    }
+}