Fix error on write request with incorrect timed request flag

Please see
#33952 (comment)

This was changed in the spec, but not in the SDK or unit tests.

The unit test here covers this, but we should consider adding it to
the cert testing as well. Please see
CHIP-Specifications/chip-test-plans#4256

src/app/WriteHandler.cpp

@@ -587,8 +587,8 @@ Status WriteHandler::ProcessWriteRequest(System::PacketBufferHandle && aPayload,
     if (mIsTimedRequest != aIsTimedWrite)
     {
         // The message thinks it should be part of a timed interaction but it's
-        // not, or vice versa.  Spec says to Respond with UNSUPPORTED_ACCESS.
-        status = Status::UnsupportedAccess;
+        // not, or vice versa.
+        status = Status::TimedRequestMismatch;
         goto exit;
     }
 

src/app/tests/TestWriteInteraction.cpp

@@ -328,7 +328,7 @@ TEST_F(TestWriteInteraction, TestWriteHandler)
             }
             else
             {
-                EXPECT_EQ(status, Status::UnsupportedAccess);
+                EXPECT_EQ(status, Status::TimedRequestMismatch);
             }
 
             mpTestContext->DrainAndServiceIO();