title: How do `Map<String, String>` get to know, the `String` endings in `MethodChannel` arguments
body: <p>If dart and kotlin code communicate through binary(array of 8-bit integers (0-255)), then how does <code>String</code> end or even <code>int</code> end is represented in, or determined from binary sequence of bytes, is there some special charCode or something else.</p>
  <p>Also is there a way to save a <code>List&lt;int&gt;</code> as-it-is to a <code>file.txt</code>, so it can be read directly to <code>List&lt;int&gt;</code> instead of serialization.</p>
  <p>Please guide this new dev,
  Thanking you...</p>