Add LEANBACK_LAUNCHER category for Android TV compatibility.

Author: heiher

app/src/main/AndroidManifest.xml

@@ -26,6 +26,7 @@
 			<intent-filter>
 				<action android:name="android.intent.action.MAIN"/>
 				<category android:name="android.intent.category.LAUNCHER"/>
+				<category android:name="android.intent.category.LEANBACK_LAUNCHER" />
 			</intent-filter>
 		</activity>
 		<activity android:name=".AppListActivity" android:label="@string/app_name"/>