Set saved image date modified value to current time

Fixes #10070

app/src/main/java/eu/kanade/tachiyomi/data/saver/ImageSaver.kt

@@ -22,6 +22,7 @@ import java.io.ByteArrayInputStream
 import java.io.ByteArrayOutputStream
 import java.io.File
 import java.io.InputStream
+import java.util.Date
 
 class ImageSaver(
     val context: Context,
@@ -77,6 +78,7 @@ class ImageSaver(
             MediaStore.Images.Media.RELATIVE_PATH to relativePath,
             MediaStore.Images.Media.DISPLAY_NAME to image.name,
             MediaStore.Images.Media.MIME_TYPE to type.mime,
+            MediaStore.Images.Media.DATE_MODIFIED to Date().time * 1000,
         )
 
         val picture = findUriOrDefault(relativePath, filename) {