Implement PlaceholderColor property in SearchBarHandlers

- Implement PlaceholderColor property in SearchBarHandlers (dotnet#1512)

Author: rookiejava

src/Core/src/Handlers/SearchBar/SearchBarHandler.Tizen.cs

@@ -49,6 +49,11 @@ public static void MapPlaceholder(SearchBarHandler handler, ISearchBar searchBar
 			handler.NativeView?.UpdatePlaceholder(searchBar);
 		}
 
+		public static void MapPlaceholderColor(SearchBarHandler handler, ISearchBar searchBar)
+		{
+			handler.NativeView?.UpdatePlaceholderColor(searchBar);
+		}
+
 		public static void MapFont(SearchBarHandler handler, ISearchBar searchBar)
 		{
 			var fontManager = handler.GetRequiredService<IFontManager>();

src/Core/src/Platform/Tizen/EntryExtensions.cs

@@ -72,6 +72,11 @@ public static void UpdatePlaceholder(this Entry nativeEntry, ITextInput entry)
 			nativeEntry.Placeholder = entry.Placeholder ?? string.Empty;
 		}
 
+		public static void UpdatePlaceholderColor(this Entry nativeEntry, ITextInput entry)
+		{
+			nativeEntry.PlaceholderColor = entry.PlaceholderColor.ToNative();
+		}
+
 		public static void UpdateIsReadOnly(this Entry nativeEntry, ITextInput entry)
 		{
 			nativeEntry.IsEditable = !entry.IsReadOnly;