Migrate TreeTraverserTest to instrumented tests

Bug: 170331260
Test: atest CarRotaryControllerUnitTests
Change-Id: I3922e22fc479355bddf78babac2a9f6c146a1935
Merged-In: I3922e22fc479355bddf78babac2a9f6c146a1935
diff --git a/Android.bp b/Android.bp
index 1c3e06e..7c3a17e 100644
--- a/Android.bp
+++ b/Android.bp
@@ -51,6 +51,7 @@
     srcs: ["src/**/*.java"],
 
     resource_dirs: [
+        "tests/unit/res",
         "res",
     ],