Increase test coverage for NotificationChannel

Test: cts
Bug: 149361682
Change-Id: I548e42800cf89a225ef1030c53cbbce6ae9a0116

api/test-current.txt

@@ -427,6 +427,7 @@ package android.app {
     method public boolean isBlockableSystem();
     method public boolean isImportanceLockedByCriticalDeviceFunction();
     method public boolean isImportanceLockedByOEM();
+    method public void lockFields(int);
     method public void setBlockableSystem(boolean);
     method public void setDeleted(boolean);
     method public void setFgServiceShown(boolean);
@@ -434,6 +435,7 @@ package android.app {
     method public void setImportanceLockedByOEM(boolean);
     method public void setImportantConversation(boolean);
     method public void setOriginalImportance(int);
+    field public static final int USER_LOCKED_SOUND = 32; // 0x20
   }
 
   public final class NotificationChannelGroup implements android.os.Parcelable {

core/java/android/app/NotificationChannel.java

@@ -134,6 +134,7 @@ public final class NotificationChannel implements Parcelable {
      * @hide
      */
     @SystemApi
+    @TestApi
     public static final int USER_LOCKED_SOUND = 0x00000020;
 
     /**
@@ -331,6 +332,7 @@ public final class NotificationChannel implements Parcelable {
     /**
      * @hide
      */
+    @TestApi
     public void lockFields(int field) {
         mUserLockedFields |= field;
     }