[Sheriff] Revert "Files app: Enable JS modules by default"

This reverts commit cfd230fd.

Reason for revert: Speculative due to https://crbug.com/1169160
Original change's description:
> Files app: Enable JS modules by default
>
> Bug: 1133186
> Change-Id: I4a92f4f60ce7b98ef3bc8f35e115eab428dda298
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2639351
> Commit-Queue: Luciano Pacheco <lucmult@chromium.org>
> Reviewed-by: Jeremie Boulic <jboulic@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#845564}

TBR=lucmult@chromium.org,chromium-scoped@luci-project-accounts.iam.gserviceaccount.com,jboulic@chromium.org

Change-Id: I62ac3ac7851d7e7e5fa52f944c2d8e6ab3b2705a
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 1133186
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2643021Reviewed-by: Leonard Grey <lgrey@chromium.org>
Commit-Queue: Leonard Grey <lgrey@chromium.org>
Cr-Commit-Position: refs/heads/master@{#845651}

chromeos/constants/chromeos_features.cc

@@ -322,7 +322,7 @@ const base::Feature kFilesNG{"FilesNG", base::FEATURE_ENABLED_BY_DEFAULT};
 
 // Enables JS modules for Files app.
 const base::Feature kFilesJsModules{"FilesJsModules",
-                                    base::FEATURE_ENABLED_BY_DEFAULT};
+                                    base::FEATURE_DISABLED_BY_DEFAULT};
 
 // Enables JS modules for Audio Player.
 const base::Feature kAudioPlayerJsModules{"AudioPlayerJsModules",