Check for GL errors after glClear and glDrawArrays.

These methods can cause errors so we should check for them.
https://www.khronos.org/registry/OpenGL-Refpages/es2.0/xhtml/glClear.xml
https://www.khronos.org/registry/OpenGL-Refpages/es2.0/xhtml/glDrawArrays.xml

PiperOrigin-RevId: 437218519

libraries/transformer/src/main/java/androidx/media3/transformer/AdvancedFrameProcessor.java

@@ -127,8 +127,10 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
     glProgram.bindAttributesAndUniforms();
     glProgram.bindAttributesAndUniforms();
     GLES20.glClearColor(/* red= */ 0, /* green= */ 0, /* blue= */ 0, /* alpha= */ 0);
     GLES20.glClearColor(/* red= */ 0, /* green= */ 0, /* blue= */ 0, /* alpha= */ 0);
     GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
     GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
+    GlUtil.checkGlError();
     // The four-vertex triangle strip forms a quad.
     // The four-vertex triangle strip forms a quad.
     GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, /* first= */ 0, /* count= */ 4);
     GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, /* first= */ 0, /* count= */ 4);
+    GlUtil.checkGlError();
   }
   }
 
 
   @Override
   @Override