Add subtype for priority

Intended to use with SliceItem type int to note the priority of an item
(such as an action) within a template.

Test: none
Bug: 68378561
Change-Id: I109adf4ea77638b7d27f3aaa7f8eb1c325287f0c
diff --git a/api/current.txt b/api/current.txt
index 5df52b9..f89df61 100644
--- a/api/current.txt
+++ b/api/current.txt
@@ -7034,6 +7034,7 @@
     field public static final java.lang.String HINT_TITLE = "title";
     field public static final java.lang.String SUBTYPE_COLOR = "color";
     field public static final java.lang.String SUBTYPE_MESSAGE = "message";
+    field public static final java.lang.String SUBTYPE_PRIORITY = "priority";
     field public static final java.lang.String SUBTYPE_SLIDER = "slider";
     field public static final java.lang.String SUBTYPE_SOURCE = "source";
     field public static final java.lang.String SUBTYPE_TOGGLE = "toggle";
diff --git a/core/java/android/app/slice/Slice.java b/core/java/android/app/slice/Slice.java
index 1aff7e9..ccb77c67 100644
--- a/core/java/android/app/slice/Slice.java
+++ b/core/java/android/app/slice/Slice.java
@@ -182,6 +182,10 @@
      * which can be retrieved to see the new state of the toggle.
      */
     public static final String SUBTYPE_TOGGLE = "toggle";
+    /**
+     * Subtype to tag an item representing priority.
+     */
+    public static final String SUBTYPE_PRIORITY = "priority";
 
     private final SliceItem[] mItems;
     private final @SliceHint String[] mHints;