Gradle 8 / AGP 8 requires Java / Kotlin module

The top level gradle project needs a Java / Kotlin module, otherwise
it skipped publishing an .aar file. While there is no code, projects
consuming this SDK look for it.
  * Maybe we can omit the .aar on in the future for this top level
  project but keeping it working the same for now.

Built SDK with Java 17 and tested publishing with a staging build with:
 * Java 11
 * Gradle 7.3.3
 * APG 7.2.2
 * Android 5 & 14 Emulator

WARNING:
 It is still recommended building with Java 17 instead of 21
 when publishing, as those on older version of R8 will get this
 build error:
 * Cannot invoke "String.length()" because "<parameter1>" is null
 * See https://stackoverflow.com/q/77788162

Author: jkasten2

OneSignalSDK/onesignal/build.gradle

@@ -1,5 +1,9 @@
 plugins {
     id 'com.android.library'
+    // There isn't Kotlin or Java code in this top-level project,
+    // however consumers look for an .aar file, which this causes it
+    // to be created.
+    id 'kotlin-android'
 }
 
 android {
@@ -25,6 +29,8 @@ android {
         targetCompatibility JavaVersion.VERSION_1_8
     }
     namespace 'com.onesignal'
+
+    kotlinOptions.freeCompilerArgs += ['-module-name', namespace]
 }
 
 ext {