Add category for voicemail that can be used to filter notifications

Test: Build test and flag tested via adb
Bug: 322806700
Change-Id: I7b4a8def72bbf69ba039c516dfa0303648b70a2f
diff --git a/core/api/current.txt b/core/api/current.txt
index 89c7728..a78fe5440 100644
--- a/core/api/current.txt
+++ b/core/api/current.txt
@@ -6352,6 +6352,7 @@
     field public static final String CATEGORY_STOPWATCH = "stopwatch";
     field public static final String CATEGORY_SYSTEM = "sys";
     field public static final String CATEGORY_TRANSPORT = "transport";
+    field @FlaggedApi("android.app.category_voicemail") public static final String CATEGORY_VOICEMAIL = "voicemail";
     field public static final String CATEGORY_WORKOUT = "workout";
     field @ColorInt public static final int COLOR_DEFAULT = 0; // 0x0
     field @NonNull public static final android.os.Parcelable.Creator<android.app.Notification> CREATOR;
diff --git a/core/java/android/app/Notification.java b/core/java/android/app/Notification.java
index a81ad3c..d705eeb 100644
--- a/core/java/android/app/Notification.java
+++ b/core/java/android/app/Notification.java
@@ -1061,6 +1061,12 @@
     public static final String CATEGORY_MISSED_CALL = "missed_call";
 
     /**
+     * Notification category: voicemail.
+     */
+    @FlaggedApi(Flags.FLAG_CATEGORY_VOICEMAIL)
+    public static final String CATEGORY_VOICEMAIL = "voicemail";
+
+    /**
      * One of the predefined notification categories (see the <code>CATEGORY_*</code> constants)
      * that best describes this Notification.  May be used by the system for ranking and filtering.
      */
diff --git a/core/java/android/app/notification.aconfig b/core/java/android/app/notification.aconfig
index d11c6c5..a5d4a14 100644
--- a/core/java/android/app/notification.aconfig
+++ b/core/java/android/app/notification.aconfig
@@ -43,3 +43,10 @@
   description: "Fixes the behavior of KeyguardManager#setPrivateNotificationsAllowed()"
   bug: "309920145"
 }
+
+flag {
+  name: "category_voicemail"
+  namespace: "wear_sysui"
+  description: "Adds a new voicemail category for notifications"
+  bug: "322806700"
+}