Simplify TrackExporter interface.

src/main/java/de/dennisguse/opentracks/io/file/exporter/CSVTrackExporter.java

@@ -23,8 +23,6 @@ import androidx.annotation.NonNull;
 import java.io.OutputStream;
 import java.io.PrintWriter;
 import java.text.NumberFormat;
-import java.util.Arrays;
-import java.util.Collections;
 import java.util.List;
 import java.util.Locale;
 import java.util.function.Function;
@@ -86,11 +84,6 @@ public class CSVTrackExporter implements TrackExporter {
         this.contentProviderUtils = contentProviderUtils;
     }
 
-    @Override
-    public boolean writeTrack(Track track, @NonNull OutputStream outputStream) {
-        return writeTrack(List.of(track), outputStream);
-    }
-
     @Override
     public boolean writeTrack(@NonNull List<Track> tracks, @NonNull OutputStream outputStream) {
         List<Column> columns = List.of(

src/main/java/de/dennisguse/opentracks/io/file/exporter/GPXTrackExporter.java

@@ -97,11 +97,6 @@ public class GPXTrackExporter implements TrackExporter {
         this.creator = creator;
     }
 
-    @Override
-    public boolean writeTrack(Track track, @NonNull OutputStream outputStream) {
-        return writeTrack(List.of(track), outputStream);
-    }
-
     @Override
     public boolean writeTrack(List<Track> tracks, @NonNull OutputStream outputStream) {
         try {

src/main/java/de/dennisguse/opentracks/io/file/exporter/KMLTrackExporter.java

@@ -99,10 +99,6 @@ public class KMLTrackExporter implements TrackExporter {
         this.contentProviderUtils = contentProviderUtils;
     }
 
-    public boolean writeTrack(Track track, @NonNull OutputStream outputStream) {
-        return writeTrack(List.of(track), outputStream);
-    }
-
     public boolean writeTrack(List<Track> tracks, @NonNull OutputStream outputStream) {
         try {
             prepare(outputStream);

src/main/java/de/dennisguse/opentracks/io/file/exporter/KmzTrackExporter.java

@@ -64,11 +64,6 @@ public class KmzTrackExporter implements TrackExporter {
         this.exportPhotos = exportPhotos;
     }
 
-    @Override
-    public boolean writeTrack(Track track, @NonNull OutputStream outputStream) {
-        return writeTrack(List.of(track), outputStream);
-    }
-
     @Override
     public boolean writeTrack(List<Track> tracks, @NonNull OutputStream outputStream) {
         try (ZipOutputStream zipOutputStream = new ZipOutputStream(outputStream)) {

src/main/java/de/dennisguse/opentracks/io/file/exporter/TrackExporter.java

@@ -31,7 +31,4 @@ import de.dennisguse.opentracks.data.models.Track;
 public interface TrackExporter {
 
     boolean writeTrack(List<Track> tracks, @NonNull OutputStream outputStream);
-
-    @Deprecated // Only used for tests
-    boolean writeTrack(Track track, @NonNull OutputStream outputStream);
 }