Fix Dackka/Metalava errors in the effects module

Public methods may only refer to public types in their signature. This
change ensures that by switching to a public supertype everywhere.

PiperOrigin-RevId: 485568625
(cherry picked from commit 3fdfe585)

library/effect/src/main/java/com/google/android/exoplayer2/effect/ColorLut.java

@@ -42,7 +42,7 @@ public interface ColorLut extends GlEffect {
   /** This method must be executed on the same thread as other GL commands. */
   @Override
   @WorkerThread
-  default ColorLutProcessor toGlTextureProcessor(Context context, boolean useHdr)
+  default SingleFrameGlTextureProcessor toGlTextureProcessor(Context context, boolean useHdr)
       throws FrameProcessingException {
     return new ColorLutProcessor(context, /* colorLut= */ this, useHdr);
   }

library/effect/src/main/java/com/google/android/exoplayer2/effect/HslAdjustment.java

@@ -111,7 +111,7 @@ public class HslAdjustment implements GlEffect {
   }
 
   @Override
-  public HslProcessor toGlTextureProcessor(Context context, boolean useHdr)
+  public SingleFrameGlTextureProcessor toGlTextureProcessor(Context context, boolean useHdr)
       throws FrameProcessingException {
     return new HslProcessor(context, /* hslAdjustment= */ this, useHdr);
   }

library/effect/src/main/java/com/google/android/exoplayer2/effect/RgbFilter.java

@@ -89,7 +89,7 @@ public class RgbFilter implements RgbMatrix {
   }
 
   @Override
-  public MatrixTextureProcessor toGlTextureProcessor(Context context, boolean useHdr)
+  public SingleFrameGlTextureProcessor toGlTextureProcessor(Context context, boolean useHdr)
       throws FrameProcessingException {
     checkForConsistentHdrSetting(useHdr);
     return RgbMatrix.super.toGlTextureProcessor(context, useHdr);

library/effect/src/main/java/com/google/android/exoplayer2/effect/RgbMatrix.java

@@ -38,7 +38,7 @@ public interface RgbMatrix extends GlEffect {
   float[] getMatrix(long presentationTimeUs, boolean useHdr);
 
   @Override
-  default MatrixTextureProcessor toGlTextureProcessor(Context context, boolean useHdr)
+  default SingleFrameGlTextureProcessor toGlTextureProcessor(Context context, boolean useHdr)
       throws FrameProcessingException {
     return MatrixTextureProcessor.create(
         context,

library/effect/src/main/java/com/google/android/exoplayer2/effect/SingleColorLut.java

@@ -147,7 +147,7 @@ public class SingleColorLut implements ColorLut {
   }
 
   @Override
-  public ColorLutProcessor toGlTextureProcessor(Context context, boolean useHdr)
+  public SingleFrameGlTextureProcessor toGlTextureProcessor(Context context, boolean useHdr)
       throws FrameProcessingException {
     checkState(!useHdr, "HDR is currently not supported.");