Android: Remove duplicate source file

Tbr: ender@google.com
Bug: None
Change-Id: Iba7a0e122310d7f7ba286dfd4c4296610a4f9bb0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2042296Reviewed-by: Peter Wen <wnwen@chromium.org>
Commit-Queue: Peter Wen <wnwen@chromium.org>
Auto-Submit: Peter Wen <wnwen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#739112}

chrome/android/chrome_java_sources.gni

@@ -1601,7 +1601,6 @@ chrome_java_sources = [
   "java/src/org/chromium/chrome/browser/tab/TabFavicon.java",
   "java/src/org/chromium/chrome/browser/tab/TabFeatureUtilities.java",
   "java/src/org/chromium/chrome/browser/tab/TabHelpers.java",
-  "java/src/org/chromium/chrome/browser/tab/TabHelpers.java",
   "java/src/org/chromium/chrome/browser/tab/TabHidingType.java",
   "java/src/org/chromium/chrome/browser/tab/TabIdManager.java",
   "java/src/org/chromium/chrome/browser/tab/TabImpl.java",