Enable watchosDeviceArm64 by default for watchos

Relnote: Adds support for watchosDeviceArm64 KMP target and target kotlin 1.9
Test: None
Bug: 364652024
Change-Id: Icf15d056ce2380ca3c733fb1a93fd502f60b40e4
diff --git a/window/window-rxjava2/build.gradle b/window/window-rxjava2/build.gradle
index 01a72dd..6477bf6 100644
--- a/window/window-rxjava2/build.gradle
+++ b/window/window-rxjava2/build.gradle
@@ -21,8 +21,9 @@
  * Please use that script when creating a new project, rather than copying an existing project and
  * modifying its settings.
  */
+
+import androidx.build.KotlinTarget
 import androidx.build.LibraryType
-import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
 
 plugins {
     id("AndroidXPlugin")
@@ -57,4 +58,5 @@
     inceptionYear = "2021"
     description = "WindowManager RxJava 2"
     legacyDisableKotlinStrictApiMode = true
+    kotlinTarget = KotlinTarget.KOTLIN_1_9
 }