[Explore sites]: Rename class referenced in xml to fix crash

Bug: 875397
Change-Id: I81cb4f819916dfd0dfd6e3e6e51e7293a7d62951
Reviewed-on: https://chromium-review.googlesource.com/1180618Reviewed-by: Theresa <twellington@chromium.org>
Commit-Queue: Cathy Li <chili@chromium.org>
Cr-Commit-Position: refs/heads/master@{#584506}

chrome/android/java/res/layout/experimental_explore_sites_category_tile_view.xml

@@ -4,7 +4,7 @@
      found in the LICENSE file. -->
 
 <!-- An explore sites section tile. -->
-<org.chromium.chrome.browser.explore_sites.ExploreSitesCategoryTileView
+<org.chromium.chrome.browser.explore_sites.ExperimentalExploreSitesCategoryTileView
     xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
@@ -28,4 +28,4 @@
         android:layout_height="wrap_content"
         android:gravity="center_horizontal"
         android:textAppearance="@style/BlackCaptionDefault" />
-</org.chromium.chrome.browser.explore_sites.ExploreSitesCategoryTileView>
+</org.chromium.chrome.browser.explore_sites.ExperimentalExploreSitesCategoryTileView>