Android: Split out media router from chrome_java

- Rename chrome/android/modules to chrome/android/features.
- Create a new media_router java target that includes everything under
  org.chromium.chrome.browser.media.router.*.
  - Move these new files into //chrome/android/features/media_router.
  - Creating separate strings and resources.
  - Add new TextAppearance (with existing values) for presubmit.
  - Split out media router's java tests and junit tests.
    - Add java tests to chrome_public_test_apk.
    - Add junit tests to buildbots.
  - Add media_router's java target to all apks.

Bug: 846440
Change-Id: I97b268da9184c3cea9315494112803c671f55b9a
Reviewed-on: https://chromium-review.googlesource.com/c/1481740
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Reviewed-by: John Budorick <jbudorick@chromium.org>
Reviewed-by: Tibor Goldschwendt <tiborg@chromium.org>
Reviewed-by: Ted Choc <tedchoc@chromium.org>
Reviewed-by: Theresa <twellington@chromium.org>
Commit-Queue: Peter Wen <wnwen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#636024}

diff --git a/BUILD.gn b/BUILD.gn
index c312373..ef5e257b 100644
--- a/BUILD.gn
+++ b/BUILD.gn

@@ -352,6 +352,7 @@
         "//chrome/android:chrome_junit_tests",
         "//chrome/android:chrome_public_apk",
         "//chrome/android:chrome_public_test_apk",
+        "//chrome/android/features/media_router:media_router_junit_tests",
         "//chrome/test/chromedriver/test/webview_shell:chromedriver_webview_shell_apk",
         "//content/shell/android:content_shell_test_apk",
         "//third_party/custom_tabs_client:custom_tabs_client_example_apk",