Select the downstream ImageEditor DFM when available

The actual screenshot image editor implementation lives downstream in
Clank and should be used over the upstream implementation.

See go/chrome-screenshotz-dd

Bug: 1024586
Change-Id: Ia79a8ea9b9d95e40a5965168be435d325dc68b5f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1931270
Commit-Queue: Kristi Park <kristipark@chromium.org>
Reviewed-by: Tibor Goldschwendt <tiborg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#718799}

chrome/android/modules/image_editor/internal/BUILD.gn

@@ -11,7 +11,13 @@ android_library("java") {
 
   deps = [
     "//chrome/android/modules/image_editor/public:java",
-    "//chrome/browser/image_editor/internal:java",
     "//chrome/browser/image_editor/public:java",
   ]
+
+  # The actual feature implementation lives downstream.
+  if (enable_chrome_android_internal) {
+    deps += [ "//clank/browser/image_editor/internal:java" ]
+  } else {
+    deps += [ "//chrome/browser/image_editor/internal:java" ]
+  }
 }