input: Write a function to create an application using Python and Flask that submits form data containing Name, Email, and Phone, and stores it in a database. If the form data is successfully stored, the function should return 'Form submitted successfully'. If the database insertion fails, the function should return 'Database insertion failed'. If the form data is empty, the function should return 'Form data is empty'.
  
  assert create_flask_app([]) == 'Form data is empty'
  assert create_flask_app({'name': 'John Doe', 'email': 'john@example.com', 'phone': '1234567890'}) == 'Form submitted successfully'
  assert create_flask_app({'name': '', 'email': 'jane@example.com', 'phone': '0987654321'}) == 'Form data is empty'
  assert create_flask_app({'name': 'Alice', 'email': 'alice@example.com', 'phone': '5555555555'}) == 'Form submitted successfully'
  assert create_flask_app({'name': 'Bob', 'email': '', 'phone': '1111111111'}) == 'Form data is empty'
output: def create_flask_app(form_data):
      if not form_data or not form_data.get('name') or not form_data.get('email') or not form_data.get('phone'):
          return 'Form data is empty'
      try:
          # Assuming a database insertion operation here
          # For example: db.insert(form_data)
          return 'Form submitted successfully'
      except:
          return 'Database insertion failed'