Code cleanup using static code analysis (Android Studio).

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

@@ -384,10 +384,7 @@ public class GPXTrackExporter implements TrackExporter {
 
         printWriter.println("</trkpt>");
 
-        if (cumulativeDistance != null) {
-            return cumulativeDistance;
-        }
-        return Distance.ZERO;
+        return Objects.requireNonNullElse(cumulativeDistance, Distance.ZERO);
     }
 
     private Double cumulateSensorData(TrackPoint trackPoint, List<TrackPoint> sensorPoints, Function<TrackPoint, Double> map) {

src/main/java/de/dennisguse/opentracks/sensors/driver/BoschEbikeParser.java

@@ -7,6 +7,7 @@ import androidx.annotation.Nullable;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
+import java.util.Objects;
 import java.util.UUID;
 
 import de.dennisguse.opentracks.data.models.Cadence;
@@ -98,7 +99,7 @@ public final class BoschEbikeParser {
                 .filter(BoschEbikeParser::isValidFrame)
                 .filter(BoschEbikeParser::isSupportedFrame)
                 .map(BoschEbikeParser::decodeFrame)
-                .filter(decodedFrame -> decodedFrame != null)
+                .filter(Objects::nonNull)
                 .reduce(null,
                         BoschEbikeParser::processMessage,
                         (left, right) -> right);

src/main/java/de/dennisguse/opentracks/settings/ImportExportSettingsFragment.java

@@ -58,7 +58,6 @@ public class ImportExportSettingsFragment extends PreferenceFragmentCompat {
         if (!healthConnectAvailable) {
             findPreference(getString(R.string.post_workout_export_health_connect_enabled_key))
                     .setSummary(R.string.health_connect_not_available);
-            return;
         }
     }
 

src/main/java/de/dennisguse/opentracks/util/FileUtils.java

@@ -27,7 +27,6 @@ import java.io.File;
 import java.io.FileDescriptor;
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
-import java.nio.channels.FileChannel;
 import java.util.ArrayList;
 import java.util.List;