optimize imports

Signed-off-by: alex <alex.plutta@googlemail.com>
Signed-off-by: Andy Scherzinger <info@andy-scherzinger.de>

src/main/java/com/owncloud/android/ui/activities/ActivitiesActivity.java

@@ -41,7 +41,6 @@ import com.owncloud.android.ui.activities.data.files.FilesRepository;
 import com.owncloud.android.ui.activity.FileActivity;
 import com.owncloud.android.ui.activity.FileDisplayActivity;
 import com.owncloud.android.ui.adapter.ActivityListAdapter;
-import com.owncloud.android.ui.adapter.StickyHeaderAdapter;
 import com.owncloud.android.ui.interfaces.ActivityListInterface;
 import com.owncloud.android.ui.preview.PreviewImageActivity;
 import com.owncloud.android.ui.preview.PreviewImageFragment;
@@ -61,7 +60,7 @@ import butterknife.BindView;
 import butterknife.ButterKnife;
 import butterknife.Unbinder;
 
-public class ActivitiesActivity extends FileActivity implements ActivityListInterface, ActivityListElement, ActivitiesContract.View {
+public class ActivitiesActivity extends FileActivity implements ActivityListInterface, ActivitiesContract.View {
     private static final String TAG = ActivitiesActivity.class.getSimpleName();
 
     @BindView(R.id.empty_list_view)

src/main/java/com/owncloud/android/ui/activities/ActivityListItemDecoration.java

@@ -2,13 +2,10 @@ package com.owncloud.android.ui.activities;
 
 import android.graphics.Canvas;
 import android.graphics.Color;
-import android.util.Log;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 
-import com.owncloud.android.R;
-
 import com.owncloud.android.ui.adapter.StickyHeaderAdapter;
 
 import androidx.annotation.NonNull;

src/main/java/com/owncloud/android/ui/adapter/ActivityListAdapter.java

@@ -65,7 +65,6 @@ import com.owncloud.android.lib.resources.activities.models.PreviewObject;
 import com.owncloud.android.lib.resources.files.FileUtils;
 import com.owncloud.android.lib.resources.status.OCCapability;
 import com.owncloud.android.lib.resources.status.OwnCloudVersion;
-import com.owncloud.android.ui.activities.ActivityListHeader;
 import com.owncloud.android.ui.interfaces.ActivityListInterface;
 import com.owncloud.android.utils.DisplayUtils;
 import com.owncloud.android.utils.MimeTypeUtil;
@@ -80,7 +79,6 @@ import java.util.List;
 import java.util.Locale;
 
 import androidx.annotation.NonNull;
-import androidx.recyclerview.widget.LinearLayoutManager;
 import androidx.recyclerview.widget.RecyclerView;
 
 /**