bill-of-materials: update 'grpc' LICENSE

Signed-off-by: Gyu-Ho Lee <gyuhox@gmail.com>

bill-of-materials.json

@@ -358,8 +358,8 @@
 		"project": "google.golang.org/grpc",
 		"licenses": [
 			{
-				"type": "BSD 3-clause \"New\" or \"Revised\" License",
-				"confidence": 0.979253112033195
+				"type": "Apache License 2.0",
+				"confidence": 1
 			}
 		]
 	},