[Android] Create and use feature list for //components/external_intents

This CL eliminates the last //chrome dependence of
ExternalNavigationHandler.java, on ChromeFeatureList.java. To do so it
componentizes the one feature that ExternalNavigationHandler uses into
//components/external_intents via a minimal
ExternalIntentsFeatureList.java.

Bug: 1031465
Change-Id: If3c81a1d03516a4d71a98126c939255f74296616
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2096559
Commit-Queue: Colin Blundell <[email protected]>
Reviewed-by: Henrique Nakashima <[email protected]>
Reviewed-by: Michael Thiessen <[email protected]>
Cr-Commit-Position: refs/heads/master@{#749130}
diff --git a/chrome/browser/DEPS b/chrome/browser/DEPS
index 63cbb23..44c8186 100644
--- a/chrome/browser/DEPS
+++ b/chrome/browser/DEPS
@@ -98,6 +98,7 @@
   "+components/embedder_support",
   "+components/encrypted_messages",
   "+components/exo",
+  "+components/external_intents",
   "+components/favicon_base",
   "+components/favicon/content",
   "+components/favicon/core",