Remove unused import

app/src/main/java/chat/rocket/android/fragment/chatroom/RoomPresenter.java

@@ -21,7 +21,6 @@ import chat.rocket.core.models.Settings;
 import chat.rocket.core.models.User;
 import chat.rocket.core.repositories.RoomRepository;
 import chat.rocket.core.repositories.UserRepository;
-import io.reactivex.BackpressureStrategy;
 import io.reactivex.Single;
 import io.reactivex.android.schedulers.AndroidSchedulers;
 import io.reactivex.disposables.Disposable;

app/src/main/java/chat/rocket/android/helper/DateTime.java

@@ -5,8 +5,6 @@ import android.text.format.DateFormat;
 
 import java.text.ParseException;
 import java.text.SimpleDateFormat;
-import java.time.Instant;
-import java.time.temporal.ChronoUnit;
 import java.util.Calendar;
 import java.util.Date;
 import java.util.GregorianCalendar;

persistence-realm/src/main/java/chat/rocket/persistence/realm/RealmHelper.java

@@ -8,8 +8,6 @@ import org.json.JSONException;
 
 import java.util.Collections;
 import java.util.List;
-import java.util.function.BiFunction;
-import java.util.function.Function;
 
 import bolts.Task;
 import bolts.TaskCompletionSource;