fix(BigQuery): null value record not returning null and causing a type mismatch on function call (#8963)

Author: Hectorhammett

BigQuery/src/ValueMapper.php

@@ -121,6 +121,10 @@ public function fromBigQuery(array $value, array $schema)
                     ? $this->int64TimestampFromBigQuery($value)
                     : $this->floatTimestampFromBigQuery($value);
             case self::TYPE_RECORD:
+                if (is_null($value)) {
+                    return null;
+                }
+
                 return $this->recordFromBigQuery($value, $schema['fields']);
             case self::TYPE_GEOGRAPHY:
                 return new Geography((string) $value);

BigQuery/tests/Unit/ValueMapperTest.php

@@ -223,6 +223,25 @@ public function bigQueryValueProvider()
                 ],
                 ['Say' => 'Hello', 'To the' => 'World']
             ],
+            [
+                [
+                    'v' => null
+                ],
+                [
+                    'type' => 'RECORD',
+                    'fields' => [
+                        [
+                            'name' => 'Say',
+                            'type' => 'STRING'
+                        ],
+                        [
+                            'name' => 'To the',
+                            'type' => 'STRING'
+                        ]
+                    ]
+                ],
+                null
+            ],
             [
                 [
                     'v' => [