Replace smart reply boolean setting with key-value list

This patch replaces the recently introduced
Settings.Global.ENABLE_SMART_REPLIES_IN_NOTIFICATIONS boolean setting
with a new Settings.Global.SMART_REPLIES_IN_NOTIFICATIONS_FLAGS
key-value list.

Rationale: This will allow us to add and tweak smart reply parameters
without polluting the global settings namespace.

Bug: 67765414
Test: atest SmartReplyConstantsTest
Change-Id: I284bb6b31618a234c4772d16ad6190a713035f1b
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/policy/SmartReplyView.java b/packages/SystemUI/src/com/android/systemui/statusbar/policy/SmartReplyView.java
index 2d829af..57fc03c 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/policy/SmartReplyView.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/policy/SmartReplyView.java
@@ -12,6 +12,7 @@
 import android.widget.Button;
 import android.widget.LinearLayout;
 
+import com.android.systemui.Dependency;
 import com.android.systemui.R;
 
 /** View which displays smart reply buttons in notifications. */
@@ -19,8 +20,11 @@
 
     private static final String TAG = "SmartReplyView";
 
+    private final SmartReplyConstants mConstants;
+
     public SmartReplyView(Context context, AttributeSet attrs) {
         super(context, attrs);
+        mConstants = Dependency.get(SmartReplyConstants.class);
     }
 
     public void setRepliesFromRemoteInput(RemoteInput remoteInput, PendingIntent pendingIntent) {