Fix Lint warnings.

Author: learnopengles

android/AndroidOpenGLESLessons/res/layout/toc_item.xml

@@ -13,7 +13,7 @@
    		android:layout_margin="8dp"
    		android:background="@drawable/icon_border"/>
    	<LinearLayout
-   		android:layout_width="match_parent"
+   		android:layout_width="0dp"
  		android:layout_height="wrap_content"
  		android:layout_weight="1"
  		android:orientation="vertical"

android/AndroidOpenGLESLessons/src/com/learnopengles/android/TableOfContents.java

@@ -9,6 +9,7 @@
 import android.app.ListActivity;
 import android.content.Intent;
 import android.os.Bundle;
+import android.util.SparseArray;
 import android.view.View;
 import android.widget.AdapterView;
 import android.widget.AdapterView.OnItemClickListener;
@@ -38,7 +39,7 @@ public void onCreate(Bundle savedInstanceState)
 
 		// Initialize data
 		final List<Map<String, Object>> data = new ArrayList<Map<String, Object>>();
-		final Map<Integer, Class<? extends Activity>> activityMapping = new HashMap<Integer, Class<? extends Activity>>();
+		final SparseArray<Class<? extends Activity>> activityMapping = new SparseArray<Class<? extends Activity>>();
 
 		int i = 0;