Enable external contribution on src/main/tools

--
MOS_MIGRATED_REVID=90052585
diff --git a/src/test/java/com/google/devtools/build/lib/testutil/BlazeTestUtils.java b/src/test/java/com/google/devtools/build/lib/testutil/BlazeTestUtils.java
index ac41beb..700e01d 100644
--- a/src/test/java/com/google/devtools/build/lib/testutil/BlazeTestUtils.java
+++ b/src/test/java/com/google/devtools/build/lib/testutil/BlazeTestUtils.java
@@ -43,12 +43,14 @@
 
     Path runfiles = directories.getFileSystem().getPath(BlazeTestUtils.runfilesDir());
     // Copy over everything in embedded_scripts.
-    Path embeddedScripts = runfiles.getRelative(TestConstants.EMBEDDED_SCRIPTS_PATH);
     Collection<Path> files = new ArrayList<>();
-    if (embeddedScripts.exists()) {
-      files.addAll(embeddedScripts.getDirectoryEntries());
-    } else {
-      System.err.println("test does not have " + embeddedScripts);
+    for (String embeddedScriptPath : TestConstants.EMBEDDED_SCRIPTS_PATHS) {
+      Path embeddedScripts = runfiles.getRelative(embeddedScriptPath);
+      if (embeddedScripts.exists()) {
+        files.addAll(embeddedScripts.getDirectoryEntries());
+      } else {
+        System.err.println("test does not have " + embeddedScripts);
+      }
     }
 
     for (Path fromFile : files) {
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.