Code cleanup: use trackFileFormat.getExtension

MyTracks/src/com/google/android/apps/mytracks/io/file/ImportActivity.java

@@ -87,8 +87,7 @@ public class ImportActivity extends Activity {
       return;
     }
     if (importAll) {
-      path = FileUtils.buildExternalDirectoryPath(
-          trackFileFormat == TrackFileFormat.KML ? "kml" : "gpx");
+      path = FileUtils.buildExternalDirectoryPath(trackFileFormat.getExtension());
       if (!FileUtils.isDirectory(new File(path))) {
         Toast.makeText(this, getString(R.string.import_no_directory, path), Toast.LENGTH_LONG)
             .show();

MyTracks/src/com/google/android/apps/mytracks/io/file/SaveActivity.java

@@ -81,7 +81,7 @@ public class SaveActivity extends Activity {
     }
 
     directoryName = playTrack ? FileUtils.buildExternalDirectoryPath(
-        trackFileFormat.getExtension(), "tmp")
+        trackFileFormat.getExtension(), FileUtils.TEMP_DIR)
         : FileUtils.buildExternalDirectoryPath(trackFileFormat.getExtension());
 
     File directory = new File(directoryName);