Make diapad in the center of FocusArea

Fixes: 170631664
Test: manual
Change-Id: Ie92ee12bc691aab2aa25a000b37347c29180fd07
diff --git a/res/layout/incall_dialpad_fragment.xml b/res/layout/incall_dialpad_fragment.xml
index c66d64d..8be0029 100644
--- a/res/layout/incall_dialpad_fragment.xml
+++ b/res/layout/incall_dialpad_fragment.xml
@@ -24,6 +24,7 @@
         android:id="@+id/dialpad_focus_area"
         android:layout_height="0dp"
         android:layout_width="0dp"
+        android:gravity="center"
         app:layout_constraintTop_toTopOf="parent"
         app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintStart_toStartOf="parent"