Add `viewmodel-testing` artifact

Bug: 264602919
Test: manual
Change-Id: I48d6948a0dac2f5a1e9d98f531755b1faca898a4
diff --git a/docs-tip-of-tree/build.gradle b/docs-tip-of-tree/build.gradle
index 50e30d8..343dc5c 100644
--- a/docs-tip-of-tree/build.gradle
+++ b/docs-tip-of-tree/build.gradle
@@ -225,6 +225,7 @@
     kmpDocs(project(":lifecycle:lifecycle-viewmodel-compose"))
     docs(project(":lifecycle:lifecycle-viewmodel-ktx"))
     docs(project(":lifecycle:lifecycle-viewmodel-savedstate"))
+    kmpDocs(project(":lifecycle:lifecycle-viewmodel-testing"))
     docs(project(":loader:loader"))
     docs(project(":loader:loader-ktx"))
     // localbroadcastmanager is deprecated