TestContentProvider: Noop change to use correct constant

The constant values are the same, so this is a no-op, but for
correctness, we should pass the defined constant that the API
documents itself to accept.

PiperOrigin-RevId: 359293471

library/core/src/androidTest/java/com/google/android/exoplayer2/upstream/TestContentProvider.java

@@ -24,7 +24,6 @@ import android.net.Uri;
 import android.os.Bundle;
 import android.os.Bundle;
 import android.os.ParcelFileDescriptor;
 import android.os.ParcelFileDescriptor;
 import androidx.annotation.Nullable;
 import androidx.annotation.Nullable;
-import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.testutil.TestUtil;
 import com.google.android.exoplayer2.testutil.TestUtil;
 import java.io.FileNotFoundException;
 import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.FileOutputStream;
@@ -73,7 +72,7 @@ public final class TestContentProvider extends ContentProvider
             openPipeHelper(
             openPipeHelper(
                 uri, /* mimeType= */ null, /* opts= */ null, /* args= */ null, /* func= */ this);
                 uri, /* mimeType= */ null, /* opts= */ null, /* args= */ null, /* func= */ this);
         return new AssetFileDescriptor(
         return new AssetFileDescriptor(
-            fileDescriptor, /* startOffset= */ 0, /* length= */ C.LENGTH_UNSET);
+            fileDescriptor, /* startOffset= */ 0, AssetFileDescriptor.UNKNOWN_LENGTH);
       } else {
       } else {
         return getContext().getAssets().openFd(fileName);
         return getContext().getAssets().openFd(fileName);
       }
       }