Enable external contribution on src/main/tools

--
MOS_MIGRATED_REVID=90052585
diff --git a/src/test/java/com/google/devtools/build/lib/testutil/TestConstants.java b/src/test/java/com/google/devtools/build/lib/testutil/TestConstants.java
index 85205a6..b577e55 100644
--- a/src/test/java/com/google/devtools/build/lib/testutil/TestConstants.java
+++ b/src/test/java/com/google/devtools/build/lib/testutil/TestConstants.java
@@ -34,7 +34,8 @@
   /**
    * Location in the bazel repo where embedded binaries come from.
    */
-  public static final String EMBEDDED_SCRIPTS_PATH = "DOES-NOT-WORK-YET";
+  public static final ImmutableList<String> EMBEDDED_SCRIPTS_PATHS = ImmutableList.of(
+      "DOES-NOT-WORK-YET");
 
   /**
    * Path within runfiles tree for finding everything else.