Revert "Artifacts service: add support for license_credits.html"

This reverts commit 2ffee8ae6a2f012f1868bc902abf3b23adffcf99.

Reason for revert: Breaks all CQ / snapshot builder.
https://ci.chromium.org/ui/p/chromeos/builders/cq/cave-cq/b8843043761431824992/overview
NotADirectoryError: [Errno 20] Not a directory: '/b/s/w/ir/x/w/recipe_cleanup/chromiumos_workspace/src/build/images/cave/latest/license_credits.html'
(shutil.copytree doesn't work for a single file.)

Original change's description:
> Artifacts service: add support for license_credits.html
>
> BUG=b:191479981
> TEST=unit tests (no coverage for relevant endpoint, though)
>
> Change-Id: Ibf03f934ebed4d6f1ca537b8b2f24e79233bf1bc
> Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/2972282
> Reviewed-by: Alex Klein <saklein@chromium.org>
> Reviewed-by: George Engelbrecht <engeg@google.com>
> Tested-by: Jack Neus <jackneus@google.com>
> Commit-Queue: Jack Neus <jackneus@google.com>

Bug: b:191479981
Change-Id: I0ef950cd2ab4fc36bc5931e59c207bacb2d7f3e9
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/2994320
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
diff --git a/api/controller/sysroot.py b/api/controller/sysroot.py
index 602037a..0dc1f1e 100644
--- a/api/controller/sysroot.py
+++ b/api/controller/sysroot.py
@@ -68,21 +68,24 @@
     A list of dictionary mappings of ArtifactType to list of paths.
   """
   generated = []
-  artifact_types = {
-    in_proto.ArtifactType.BREAKPAD_DEBUG_SYMBOLS: sysroot.BundleBreakpadSymbols,
-    in_proto.ArtifactType.DEBUG_SYMBOLS: sysroot.BundleDebugSymbols
-  }
-
   for output_artifact in in_proto.output_artifacts:
-    for artifact_type, func in artifact_types.items():
-      if artifact_type in output_artifact.artifact_types:
-        result = func(chroot, sysroot_class, build_target, output_dir)
-        if result:
-          generated.append({
-              'paths': [result] if isinstance(result, str) else result,
-              'type': artifact_type,
-          })
-
+    if (in_proto.ArtifactType.BREAKPAD_DEBUG_SYMBOLS
+        in output_artifact.artifact_types):
+      result_path = sysroot.BundleBreakpadSymbols(chroot, sysroot_class,
+                                                  build_target, output_dir)
+      if result_path:
+        generated.append({
+            'paths': [result_path],
+            'type': in_proto.ArtifactType.BREAKPAD_DEBUG_SYMBOLS,
+        })
+    if in_proto.ArtifactType.DEBUG_SYMBOLS in output_artifact.artifact_types:
+      result_path = sysroot.BundleDebugSymbols(chroot, sysroot_class,
+                                               build_target, output_dir)
+      if result_path:
+        generated.append({
+            'paths': [result_path],
+            'type': in_proto.ArtifactType.DEBUG_SYMBOLS,
+        })
   return generated