Cleaned up strings.xml

Removed unused strings.

Change-Id: I4752b86795a0b03b7de33bad3d736ba3ab2d8392
diff --git a/samples/SupportLeanbackShowcase/app/src/main/res/values/strings.xml b/samples/SupportLeanbackShowcase/app/src/main/res/values/strings.xml
index 9bc6ffa..9a46e54 100644
--- a/samples/SupportLeanbackShowcase/app/src/main/res/values/strings.xml
+++ b/samples/SupportLeanbackShowcase/app/src/main/res/values/strings.xml
@@ -16,42 +16,8 @@
 <resources>
     <string name="app_name">ShowcaseApp</string>
     <string name="browse_title"><![CDATA[androidTV]]></string>
-    <string name="related_movies">Related Videos</string>
-    <string name="vertical_grid_title"><![CDATA[Vertical Video Grid]]></string>
-    <string name="error">Error</string>
-    <string name="ok">OK</string>
-    <string name="pause">Pause</string>
-    <string name="play">Play</string>
-    <string name="stop">Stop</string>
-    <string name="init_text">00:00</string>
-    <string name="play_pause_description">Play Pause Button</string>
-    <string name="loading">Loading&#8230;</string>
-    <string name="no_video_found">No video was found</string>
-    <string name="about_app">About DemoCast Player</string>
-    <string name="version">Version: %1$s</string>
-    <string name="popular_header">Popular Videos</string>
-    <string name="preferences">PREFERENCES</string>
-    <string name="grid_view">Grid View</string>
-    <string name="error_fragment">Error Fragment</string>
-    <string name="personal_settings">Personal Settings</string>
-    <string name="watch_trailer_1">Watch trailer</string>
-    <string name="watch_trailer_2">FREE</string>
-    <string name="rent_1">Rent By Day</string>
-    <string name="rent_2">From $1.99</string>
-    <string name="buy_1">Buy and Own</string>
-    <string name="buy_2">AT $9.99</string>
-    <string name="movie">Movie</string>
-    <string name="should_start">shouldStart</string>
-    <string name="start_position">startPosition</string>
-    <string name="search_results">Search Results</string>
 
     <!-- Error messages -->
-    <string name="video_error_media_load_timeout">Media loading timed out</string>
-    <string name="video_error_server_inaccessible">Media server was not reachable</string>
-    <string name="video_error_unknown_error">Failed to load video</string>
-    <string name="error_fragment_message">An error occurred</string>
-    <string name="dismiss_error">Dismiss</string>
-    <string name="oops">Oops</string>
     <string name="implement_search">Implement your own in-app search.</string>
     <string name="card_examples_title">Card Examples</string>
     <string name="detail_view_title">DetailView Example</string>