Fix SurfaceControl demo app layout

The fixes sizes could end up being wider than the screen (e.g on Pixel 3a)

PiperOrigin-RevId: 278642828

demos/surface/src/main/java/com/google/android/exoplayer2/surfacedemo/MainActivity.java

@@ -124,10 +124,10 @@ public final class MainActivity extends Activity {
       }
       gridLayout.addView(view);
       GridLayout.LayoutParams layoutParams = new GridLayout.LayoutParams();
-      layoutParams.width = 400;
-      layoutParams.height = 400;
-      layoutParams.columnSpec = GridLayout.spec(i % 3);
-      layoutParams.rowSpec = GridLayout.spec(i / 3);
+      layoutParams.width = 0;
+      layoutParams.height = 0;
+      layoutParams.columnSpec = GridLayout.spec(i % 3, 1f);
+      layoutParams.rowSpec = GridLayout.spec(i / 3, 1f);
       layoutParams.bottomMargin = 10;
       layoutParams.leftMargin = 10;
       layoutParams.topMargin = 10;

demos/surface/src/main/res/layout/main_activity.xml

@@ -20,24 +20,32 @@
   android:layout_height="match_parent"
   android:keepScreenOn="true">
 
-  <GridLayout
+  <LinearLayout
     android:layout_width="match_parent"
     android:layout_height="match_parent"
-    android:id="@+id/grid_layout"
-    android:columnCount="3" />
+    android:orientation="vertical">
 
-  <SurfaceView
+    <GridLayout
+      android:id="@+id/grid_layout"
       android:layout_width="match_parent"
-    android:layout_height="match_parent"
-    android:id="@+id/full_screen_view"
-    android:visibility="gone" />
+      android:layout_height="0dp"
+      android:layout_weight="1"
+      android:columnCount="3"/>
 
     <com.google.android.exoplayer2.ui.PlayerControlView
       android:id="@+id/player_control_view"
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       android:layout_gravity="bottom"
-    app:show_timeout="0" />
+      app:show_timeout="0"/>
+
+  </LinearLayout>
+
+  <SurfaceView
+    android:id="@+id/full_screen_view"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:visibility="gone"/>
 
 </FrameLayout>