satisfy codacy

Signed-off-by: tobiasKaminsky <tobias@kaminsky.me>

src/main/java/com/owncloud/android/ui/preview/PreviewTextFragment.java

@@ -227,7 +227,7 @@ public class PreviewTextFragment extends FileFragment implements SearchView.OnQu
         mHandler.removeCallbacksAndMessages(null);
 
         if (mOriginalText != null) {
-            if (getActivity() != null && getActivity() instanceof FileDisplayActivity) {
+            if (getActivity() instanceof FileDisplayActivity) {
                 FileDisplayActivity fileDisplayActivity = (FileDisplayActivity) getActivity();
                 fileDisplayActivity.setSearchQuery(query);
             }

src/main/java/com/owncloud/android/utils/StringUtils.java

@@ -29,7 +29,11 @@ import java.util.regex.Pattern;
 /**
  * Helper class for handling and manipulating strings.
  */
-public class StringUtils {
+public final class StringUtils {
+
+    private StringUtils() {
+        // prevent class from being constructed
+    }
 
     public static String searchAndColor(String text, String searchText, @ColorInt int color) {