Update username UX and UI.

app/src/main/java/org/thoughtcrime/securesms/preferences/widgets/UsernamePreference.java

@@ -0,0 +1,49 @@
+package org.thoughtcrime.securesms.preferences.widgets;
+
+import android.content.Context;
+import android.util.AttributeSet;
+import android.view.View;
+
+import androidx.preference.Preference;
+import androidx.preference.PreferenceViewHolder;
+
+import org.thoughtcrime.securesms.R;
+
+public class UsernamePreference extends Preference {
+
+  private View.OnLongClickListener onLongClickListener;
+
+  public UsernamePreference(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
+    super(context, attrs, defStyleAttr, defStyleRes);
+    initialize();
+  }
+
+  public UsernamePreference(Context context, AttributeSet attrs, int defStyleAttr) {
+    super(context, attrs, defStyleAttr);
+    initialize();
+  }
+
+  public UsernamePreference(Context context, AttributeSet attrs) {
+    super(context, attrs);
+    initialize();
+  }
+
+  public UsernamePreference(Context context) {
+    super(context);
+    initialize();
+  }
+
+  private void initialize() {
+    setLayoutResource(R.layout.preference_username);
+  }
+
+  public void setOnLongClickListener(View.OnLongClickListener onLongClickListener) {
+    this.onLongClickListener = onLongClickListener;
+  }
+
+  @Override
+  public void onBindViewHolder(PreferenceViewHolder holder) {
+    super.onBindViewHolder(holder);
+    holder.itemView.setOnLongClickListener(onLongClickListener);
+  }
+}