Make FrameInfo and SurfaceInfo public.

Both are used in the public FrameProcessor interface, so they
should be public too.

PiperOrigin-RevId: 463454859
(cherry picked from commit 40e96d15)

library/transformer/src/main/java/com/google/android/exoplayer2/transformer/FrameInfo.java

@@ -18,7 +18,7 @@ package com.google.android.exoplayer2.transformer;
 import static com.google.android.exoplayer2.util.Assertions.checkArgument;
 
 /** Value class specifying information about a decoded video frame. */
-/* package */ class FrameInfo {
+public class FrameInfo {
   /** The width of the frame, in pixels. */
   public final int width;
   /** The height of the frame, in pixels. */

library/transformer/src/main/java/com/google/android/exoplayer2/transformer/SurfaceInfo.java

@@ -21,7 +21,7 @@ import android.view.Surface;
 import androidx.annotation.Nullable;
 
 /** Immutable value class for a {@link Surface} and supporting information. */
-/* package */ final class SurfaceInfo {
+public final class SurfaceInfo {
 
   /** The {@link Surface}. */
   public final Surface surface;