Add toggle for Prevent Ringing setting in Gesture page.

- Replace Preference with PrimarySwitchPreference.

Fixes: 177408128
Test: open gesture page
Change-Id: I25079632459b3457995792347f4904c25374d47d
diff --git a/res/xml/gestures.xml b/res/xml/gestures.xml
index 970ad21..f18d8a5 100644
--- a/res/xml/gestures.xml
+++ b/res/xml/gestures.xml
@@ -88,7 +88,7 @@
         settings:searchable="false"
         settings:controller="com.android.settings.gestures.PickupGesturePreferenceController" />
 
-    <Preference
+    <com.android.settings.widget.PrimarySwitchPreference
         android:key="gesture_prevent_ringing_summary"
         android:title="@string/gesture_prevent_ringing_screen_title"
         android:fragment="com.android.settings.gestures.PreventRingingGestureSettings"