temporarily change ::createInsecure() back to return NULL (#25994)

src/php/ext/grpc/channel_credentials.c

@@ -233,10 +233,7 @@ PHP_METHOD(ChannelCredentials, createComposite) {
  * @return null
  */
 PHP_METHOD(ChannelCredentials, createInsecure) {
-  grpc_channel_credentials* creds = grpc_insecure_credentials_create();
-  zval* creds_object = grpc_php_wrap_channel_credentials(
-      creds, strdup("INSECURE"), false TSRMLS_CC);
-  RETURN_DESTROY_ZVAL(creds_object);
+  RETURN_NULL();
 }
 
 /**

src/php/tests/unit_tests/ChannelCredentialsTest.php

@@ -43,7 +43,7 @@ class ChanellCredentialsTest extends \PHPUnit\Framework\TestCase
     public function testCreateInsecure()
     {
         $channel_credentials = Grpc\ChannelCredentials::createInsecure();
-        $this->assertNotNull($channel_credentials);
+        $this->assertNull($channel_credentials);
     }
 
     public function testDefaultRootsPem()

src/php/tests/unit_tests/ChannelTest.php

@@ -52,7 +52,7 @@ class ChannelTest extends \PHPUnit\Framework\TestCase
         $this->assertNotNull($xdsCreds);
     }
 
-    public function testCreateXdsWithInsecure() {
+    public function disabled_testCreateXdsWithInsecure() {
         $xdsCreds = \Grpc\ChannelCredentials::createXds(
             \Grpc\ChannelCredentials::createInsecure()
         );
@@ -365,6 +365,7 @@ class ChannelTest extends \PHPUnit\Framework\TestCase
                 ),
                 50306,
             ],
+            /*
             [
                 \Grpc\ChannelCredentials::createXds(
                     \Grpc\ChannelCredentials::createInSecure()
@@ -374,6 +375,7 @@ class ChannelTest extends \PHPUnit\Framework\TestCase
                 ),
                 50307,
             ],
+            */
         ];
     }
 
@@ -436,6 +438,7 @@ class ChannelTest extends \PHPUnit\Framework\TestCase
                 ),
                 50353,
             ],
+            /*
             [
                 \Grpc\ChannelCredentials::createXds(
                     \Grpc\ChannelCredentials::createSsl()
@@ -452,6 +455,7 @@ class ChannelTest extends \PHPUnit\Framework\TestCase
                 ),
                 50355,
             ],
+            */
             [
                 \Grpc\ChannelCredentials::createSsl(),
                 \Grpc\ChannelCredentials::createXds(