style(unified-search): center load more button

Signed-off-by: alperozturk96 <alper_ozturk@proton.me>

Author: alperozturk96

app/src/main/res/layout/unified_search_footer.xml

@@ -5,12 +5,11 @@
   ~ SPDX-FileCopyrightText: 2026 Alper Ozturk <alper.ozturk@nextcloud.com>
   ~ SPDX-License-Identifier: AGPL-3.0-or-later
   -->
-<TextView xmlns:android="http://schemas.android.com/apk/res/android"
+<com.google.android.material.button.MaterialButton
+    xmlns:android="http://schemas.android.com/apk/res/android"
     android:id="@+id/unified_search_footer_layout"
+    style="@style/Widget.Material3.Button.TextButton"
     android:layout_width="match_parent"
     android:layout_height="@dimen/min_list_item_size"
-    android:gravity="center_vertical"
-    android:paddingStart="@dimen/standard_list_item_size"
-    android:paddingEnd="@dimen/standard_quarter_padding"
-    android:text="@string/load_more_results"
-    android:textColor="@color/secondary_text_color" />
+    android:gravity="center"
+    android:text="@string/load_more_results" />