Clarify that the array passed to ByteArrayContent should not be modified. (#8484)

* Clarify that the array passed to ByteArrayContent should not be modified.

* Update xml/System.Net.Http/ByteArrayContent.xml

Co-authored-by: Marie Píchová <[email protected]>

Co-authored-by: Marie Píchová <[email protected]>

Author: rzikm

xml/System.Net.Http/ByteArrayContent.xml

@@ -79,7 +79,14 @@
       <Docs>
         <param name="content">The content used to initialize the <see cref="T:System.Net.Http.ByteArrayContent" />.</param>
         <summary>Initializes a new instance of the <see cref="T:System.Net.Http.ByteArrayContent" /> class.</summary>
-        <remarks>To be added.</remarks>
+        <remarks>
+          <format type="text/markdown"><![CDATA[  
+  
+## Remarks  
+The <xref:System.Net.Http.ByteArrayContent> class does not internally copy the provided byte array but keeps a reference to it instead. Callers should not modify the data in the array until the content is sent. 
+   
+ ]]></format>
+        </remarks>
         <exception cref="T:System.ArgumentNullException">The <paramref name="content" /> parameter is <see langword="null" />.</exception>
       </Docs>
     </Member>
@@ -122,7 +129,9 @@
           <format type="text/markdown"><![CDATA[  
   
 ## Remarks  
- Only the range specified by the `offset` parameter and the `count`  parameter is used as content. Syntax  
+The <xref:System.Net.Http.ByteArrayContent> class does not internally copy the provided byte array but keeps a reference to it instead. Callers should not modify the data in the array until the content is sent. 
+   
+ Only the range specified by the `offset` parameter and the `count`  parameter is used as content.
   
  ]]></format>
         </remarks>