Add flag to control blocking Smart Replies for apps targeting an Android version below P.

Bug: 73802997

Test: atest SmartReplyConstantsTest

Change-Id: Id340cba09da7931ff6a4689802b3a5f594852a72
(cherry picked from commit 28944cbdcf15128b664ccdaed44c59d3fc64d1db)
diff --git a/packages/SystemUI/res/values/config.xml b/packages/SystemUI/res/values/config.xml
index 9ebf557..f76603b 100644
--- a/packages/SystemUI/res/values/config.xml
+++ b/packages/SystemUI/res/values/config.xml
@@ -479,6 +479,9 @@
     <!-- Smart replies in notifications: Whether smart replies in notifications are enabled. -->
     <bool name="config_smart_replies_in_notifications_enabled">true</bool>
 
+    <!-- Smart replies in notifications: Whether we disable the feature unless the app targets P -->
+    <bool name="config_smart_replies_in_notifications_requires_targeting_p">true</bool>
+
     <!-- Smart replies in notifications: Maximum number of times SmartReplyView will try to find a
          better (narrower) line-break for a double-line smart reply button. -->
     <integer name="config_smart_replies_in_notifications_max_squeeze_remeasure_attempts">3</integer>