Load demo app samples from json.

Also handle .exolist.json links. This lets you put a list of
samples somewhere (e.g. on the web). Clicking it opens the
app and displays the samples it defines.
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=123198928

demo/src/main/AndroidManifest.xml

@@ -38,6 +38,18 @@
         <action android:name="android.intent.action.MAIN"/>
         <category android:name="android.intent.category.LAUNCHER"/>
       </intent-filter>
+      <intent-filter>
+        <action android:name="android.intent.action.VIEW"/>
+        <category android:name="android.intent.category.DEFAULT"/>
+        <category android:name="android.intent.category.BROWSABLE"/>
+        <data android:scheme="http"/>
+        <data android:scheme="https"/>
+        <data android:scheme="content"/>
+        <data android:scheme="asset"/>
+        <data android:scheme="file"/>
+        <data android:host="*"/>
+        <data android:pathPattern=".*\\.exolist\\.json"/>
+      </intent-filter>
     </activity>
 
     <activity android:name="com.google.android.exoplayer.demo.PlayerActivity"

demo/src/main/java/com/google/android/exoplayer/demo/PlayerActivity.java

@@ -29,7 +29,6 @@ import com.google.android.exoplayer.SampleSource;
 import com.google.android.exoplayer.SimpleExoPlayer;
 import com.google.android.exoplayer.TrackGroupArray;
 import com.google.android.exoplayer.dash.DashSampleSource;
-import com.google.android.exoplayer.demo.ui.TrackSelectionHelper;
 import com.google.android.exoplayer.drm.DrmSessionManager;
 import com.google.android.exoplayer.drm.StreamingDrmSessionManager;
 import com.google.android.exoplayer.drm.UnsupportedDrmException;

demo/src/main/java/com/google/android/exoplayer/demo/ui/TrackSelectionHelper.java → demo/src/main/java/com/google/android/exoplayer/demo/TrackSelectionHelper.java

@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package com.google.android.exoplayer.demo.ui;
+package com.google.android.exoplayer.demo;
 
 import com.google.android.exoplayer.DefaultTrackSelector;
 import com.google.android.exoplayer.DefaultTrackSelector.TrackInfo;
@@ -22,7 +22,6 @@ import com.google.android.exoplayer.TrackGroup;
 import com.google.android.exoplayer.TrackGroupArray;
 import com.google.android.exoplayer.TrackRenderer;
 import com.google.android.exoplayer.TrackSelection;
-import com.google.android.exoplayer.demo.R;
 import com.google.android.exoplayer.util.MimeTypes;
 
 import android.annotation.SuppressLint;

demo/src/main/res/values/strings.xml

@@ -49,4 +49,6 @@
 
   <string name="storage_permission_denied">Permission to access storage was denied</string>
 
+  <string name="sample_list_load_error">One or more sample lists failed to load</string>
+
 </resources>