Switch order of literals to prevent NullPointerException (#4)

Co-authored-by: pixeebot[bot] <23113631+pixeebot@users.noreply.github.com>

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

@@ -494,7 +494,7 @@ public class KMLTrackExporter implements TrackExporter {
     }
 
     private void writeActivityType(String activityTypeLocalized) {
-        if (activityTypeLocalized == null || activityTypeLocalized.equals("")) {
+        if (activityTypeLocalized == null || "".equals(activityTypeLocalized)) {
             return;
         }
         printWriter.println("<ExtendedData>");

src/main/java/de/dennisguse/opentracks/io/file/importer/KmlTrackImporter.java

@@ -415,7 +415,7 @@ public class KmlTrackImporter extends DefaultHandler implements XMLImporter.Trac
         Float value = null;
         if (content != null) {
             content = content.trim();
-            if (!content.equals("")) {
+            if (!"".equals(content)) {
                 try {
                     value = Float.parseFloat(content);
                 } catch (NumberFormatException e) {

src/main/java/de/dennisguse/opentracks/io/file/importer/KmzTrackImporter.java

@@ -230,7 +230,7 @@ public class KmzTrackImporter {
      */
     @Deprecated //TODO Use JDK9's inputStream.transferTo() instead of manual buffer
     private void readAndSaveImageFile(ZipInputStream zipInputStream, Track.Id trackId, String fileName) throws IOException {
-        if (trackId == null || fileName.equals("")) {
+        if (trackId == null || "".equals(fileName)) {
             return;
         }