Change default long-press time to 400ms

The default long-press time has been changed from 500ms to 400ms by
b/30159825. so the values for the list of long-press timeout options
in Settings app should be changed.

Bug: 35226519
Test: manual - go to Settings > Accessibility > Touch & hold delay

Change-Id: I8e2421ea4119742bb6bf0e27688c65e3de3099dc
diff --git a/res/values/arrays.xml b/res/values/arrays.xml
index 6827e5b..5a7b42e 100644
--- a/res/values/arrays.xml
+++ b/res/values/arrays.xml
@@ -699,7 +699,7 @@
 
     <!-- Values for the list of long press timeout options. -->
     <string-array name="long_press_timeout_selector_values" translatable="false">
-        <item>500</item>
+        <item>400</item>
         <item>1000</item>
         <item>1500</item>
     </string-array>