chore:adds a dedicated flag instead of overloading the provider name parameter

Author: Boyce007

lesson_09/types/types_app/src/main/java/com/codedifferently/lesson9/Lesson9.java

@@ -32,7 +32,7 @@ public void run(String... args) throws Exception {
     }
     String path = getDataPath();
 
-    if (providerName.equals("all")) {
+    if (providerName.equals("--bulk")) {
       jsonFileGenerator.createTestFile(path, providerName);
       return;
     }