Migrate ContactSearch RV to MappingLazyColumn.

app/src/main/java/org/thoughtcrime/securesms/ContactSelectionActivity.java

@@ -34,7 +34,6 @@ import org.thoughtcrime.securesms.contacts.sync.ContactDiscovery;
 import org.thoughtcrime.securesms.recipients.RecipientId;
 import org.thoughtcrime.securesms.util.DynamicNoActionBarTheme;
 import org.thoughtcrime.securesms.util.DynamicTheme;
-import org.thoughtcrime.securesms.util.ServiceUtil;
 
 import java.io.IOException;
 import java.lang.ref.WeakReference;
@@ -49,8 +48,7 @@ import java.util.function.Consumer;
  */
 public abstract class ContactSelectionActivity extends PassphraseRequiredActivity
                                                implements SwipeRefreshLayout.OnRefreshListener,
-                                                          ContactSelectionListFragment.OnContactSelectedListener,
-                                                          ContactSelectionListFragment.ScrollCallback
+                                                          ContactSelectionListFragment.OnContactSelectedListener
 {
   private static final String TAG = Log.tag(ContactSelectionActivity.class);
 
@@ -136,17 +134,6 @@ public abstract class ContactSelectionActivity extends PassphraseRequiredActivit
   @Override
   public void onContactDeselected(@NonNull Optional<RecipientId> recipientId, String number, @NonNull Optional<ChatType> chatType) {}
 
-  @Override
-  public void onBeginScroll() {
-    hideKeyboard();
-  }
-
-  private void hideKeyboard() {
-    ServiceUtil.getInputMethodManager(this)
-               .hideSoftInputFromWindow(toolbar.getWindowToken(), 0);
-    toolbar.clearFocus();
-  }
-
   private static class RefreshDirectoryTask extends AsyncTask<Context, Void, Void> {
 
     private final WeakReference<ContactSelectionActivity> activity;