Add a HINT_KEYWORDS to Slice

Want to be able to support allowing a Slice to specify some keywords
associated with it; need a new hint to identify these.

Bug: 74086214
Test: make
Change-Id: I79d3f1806eecf416f5e3ae09451b90507b382c24

core/java/android/app/slice/Slice.java

@@ -65,7 +65,8 @@ public final class Slice implements Parcelable {
             HINT_TOGGLE,
             HINT_HORIZONTAL,
             HINT_PARTIAL,
-            HINT_SEE_MORE
+            HINT_SEE_MORE,
+            HINT_KEY_WORDS
     })
     @Retention(RetentionPolicy.SOURCE)
     public @interface SliceHint {}
@@ -148,6 +149,11 @@ public final class Slice implements Parcelable {
      * apps.
      */
     public static final String HINT_CALLER_NEEDED = "caller_needed";
+    /**
+     * A hint to indicate that the contents of this subslice represent a list of keywords
+     * related to the parent slice.
+     */
+    public static final String HINT_KEY_WORDS = "key_words";
     /**
      * Key to retrieve an extra added to an intent when a control is changed.
      */