Fixed release publishing failing to build the javadoc jar (#1024)

* Fixed release publishing failing to build the javadoc jar

AGP generates the published javadoc with Dokka 1.4.32, which cannot read the
sealed classes in livekit-uniffi-android and fails with "PermittedSubclasses
requires ASM9". Disabled AGP's javadoc generation and packaged the javadoc jar
from the project's Dokka 1.9.20 dokkaJavadoc task instead.

* Generated the javadoc into AGP's output directory instead of appending to the jar

Disabling AGP's javadoc generation left any output from an earlier build in
place, and the jar, which fails on duplicate files, then packaged it next to
the Dokka output. The generation task now syncs the Dokka output into its own
output directory, so the jar keeps its single input and stale files are
removed.

Author: adrian-niculescu

livekit-android-sdk/build.gradle

@@ -113,6 +113,27 @@ dokkaHtml {
     }
 }
 
+interface InjectedFileSystemOperations {
+    @javax.inject.Inject
+    FileSystemOperations getFs()
+}
+
+// AGP generates the published javadoc with Dokka 1.4.32, which fails to read the sealed classes
+// in livekit-uniffi-android ("PermittedSubclasses requires ASM9"). The generation task fills its
+// output directory from this project's Dokka instead, and the javadoc jar packages that directory.
+tasks.withType(com.android.build.gradle.tasks.JavaDocGenerationTask).configureEach { task ->
+    def fs = objects.newInstance(InjectedFileSystemOperations).fs
+    def dokkaJavadocOutput = files(tasks.named("dokkaJavadoc"))
+    task.inputs.files(dokkaJavadocOutput)
+    task.actions.clear()
+    task.doLast { generationTask ->
+        fs.sync {
+            from(dokkaJavadocOutput)
+            into(generationTask.outputDirectory)
+        }
+    }
+}
+
 dependencies {
     //api fileTree(dir: 'libs', include: ['*.jar'])
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"