Move cell layout tests to deviceless tests

Excluding Tapl tests

Also adding Launcher3 test assets to Launcher3TestResources

Bug: 297950111
Flag: None
Test: atest Launcher3RoboTests
Test: atest NexusLauncherRoboTests
Test: SysUI studio
Change-Id: I101fc7229252016ec7e5015ed5f6a5b4dbba894d
diff --git a/tests/Android.bp b/tests/Android.bp
index 5ec2263..11177de 100644
--- a/tests/Android.bp
+++ b/tests/Android.bp
@@ -105,6 +105,7 @@
 android_library {
     name: "Launcher3TestResources",
     resource_dirs: ["res"],
+    asset_dirs: ["assets"],
     // TODO(b/319712088): re-enable use_resource_processor
     use_resource_processor: false,
 }