Remove the added constants to fix the Semantic Version Checker build warnings.

Author: Hailong

app/code/Magento/Sales/Model/Order/Email/Sender.php

@@ -18,12 +18,6 @@
  */
 abstract class Sender
 {
-    /**
-     * Copy methods
-     */
-    const COPY_METHOD_BCC = 'bcc';
-    const COPY_METHOD_COPY = 'copy';
-
     /**
      * @var \Magento\Sales\Model\Order\Email\SenderBuilderFactory
      */
@@ -93,7 +87,7 @@ protected function checkAndSend(Order $order)
             $this->logger->error($e->getMessage());
             return false;
         }
-        if ($this->identityContainer->getCopyMethod() == self::COPY_METHOD_COPY) {
+        if ($this->identityContainer->getCopyMethod() == 'copy') {
             try {
                 $sender->sendCopyTo();
             } catch (\Exception $e) {

app/code/Magento/Sales/Model/Order/Email/SenderBuilder.php

@@ -65,7 +65,7 @@ public function send()
 
         $copyTo = $this->identityContainer->getEmailCopyTo();
 
-        if (!empty($copyTo) && $this->identityContainer->getCopyMethod() == Sender::COPY_METHOD_BCC) {
+        if (!empty($copyTo) && $this->identityContainer->getCopyMethod() == 'bcc') {
             foreach ($copyTo as $email) {
                 $this->transportBuilder->addBcc($email);
             }

app/code/Magento/Sales/Test/Unit/Model/Order/Creditmemo/Sender/EmailSenderTest.php

@@ -285,7 +285,7 @@ public function testSend($configValue, $forceSyncMode, $isComment, $emailSending
             if ($emailSendingResult) {
                 $this->identityContainerMock->expects($this->once())
                     ->method('getCopyMethod')
-                    ->willReturn($this->subject::COPY_METHOD_COPY);
+                    ->willReturn('copy');
 
                 $this->senderBuilderFactoryMock->expects($this->once())
                     ->method('create')

app/code/Magento/Sales/Test/Unit/Model/Order/Email/Sender/CreditmemoSenderTest.php

@@ -140,7 +140,7 @@ public function testSend($configValue, $forceSyncMode, $customerNoteNotify, $ema
             if ($emailSendingResult) {
                 $this->identityContainerMock->expects($this->once())
                     ->method('getCopyMethod')
-                    ->willReturn($this->sender::COPY_METHOD_COPY);
+                    ->willReturn('copy');
 
                 $this->senderBuilderFactoryMock->expects($this->once())
                     ->method('create')

app/code/Magento/Sales/Test/Unit/Model/Order/Email/Sender/InvoiceSenderTest.php

@@ -146,7 +146,7 @@ public function testSend($configValue, $forceSyncMode, $customerNoteNotify, $ema
             if ($emailSendingResult) {
                 $this->identityContainerMock->expects($this->once())
                     ->method('getCopyMethod')
-                    ->willReturn($this->sender::COPY_METHOD_COPY);
+                    ->willReturn('copy');
 
                 $this->senderBuilderFactoryMock->expects($this->once())
                     ->method('create')

app/code/Magento/Sales/Test/Unit/Model/Order/Email/Sender/OrderSenderTest.php

@@ -79,7 +79,7 @@ public function testSend($configValue, $forceSyncMode, $emailSendingResult, $sen
             if ($emailSendingResult) {
                 $this->identityContainerMock->expects($this->once())
                     ->method('getCopyMethod')
-                    ->willReturn($this->sender::COPY_METHOD_COPY);
+                    ->willReturn('copy');
 
                 $addressMock = $this->createMock(\Magento\Sales\Model\Order\Address::class);
 
@@ -220,7 +220,7 @@ public function testSendVirtualOrder($isVirtualOrder, $formatCallCount, $expecte
 
         $this->identityContainerMock->expects($this->once())
             ->method('getCopyMethod')
-            ->willReturn($this->sender::COPY_METHOD_COPY);
+            ->willReturn('copy');
 
         $addressMock = $this->createMock(\Magento\Sales\Model\Order\Address::class);
 

app/code/Magento/Sales/Test/Unit/Model/Order/Email/Sender/ShipmentSenderTest.php

@@ -146,7 +146,7 @@ public function testSend($configValue, $forceSyncMode, $customerNoteNotify, $ema
             if ($emailSendingResult) {
                 $this->identityContainerMock->expects($this->once())
                     ->method('getCopyMethod')
-                    ->willReturn($this->sender::COPY_METHOD_COPY);
+                    ->willReturn('copy');
 
                 $this->senderBuilderFactoryMock->expects($this->once())
                     ->method('create')

app/code/Magento/Sales/Test/Unit/Model/Order/Invoice/Sender/EmailSenderTest.php

@@ -284,7 +284,7 @@ public function testSend($configValue, $forceSyncMode, $isComment, $emailSending
             if ($emailSendingResult) {
                 $this->identityContainerMock->expects($this->once())
                     ->method('getCopyMethod')
-                    ->willReturn($this->subject::COPY_METHOD_COPY);
+                    ->willReturn('copy');
 
                 $this->senderBuilderFactoryMock->expects($this->once())
                     ->method('create')

app/code/Magento/Sales/Test/Unit/Model/Order/Shipment/Sender/EmailSenderTest.php

@@ -286,7 +286,7 @@ public function testSend($configValue, $forceSyncMode, $isComment, $emailSending
             if ($emailSendingResult) {
                 $this->identityContainerMock->expects($this->once())
                     ->method('getCopyMethod')
-                    ->willReturn($this->subject::COPY_METHOD_COPY);
+                    ->willReturn('copy');
 
                 $this->senderBuilderFactoryMock->expects($this->once())
                     ->method('create')