By Ellen Chang Electric vehicle maker has what it takes to last through its growing pains, argues Real Money’s Stephen ‘Sarge’ Guilfoyle. Startups have a long tradition of burning through cash before achieving profitability and their long-term growth potential. When the company is in a capital-intensive industry such as auto manufacturing, the challenge can be an order of magnitude greater. Such is the case for investors in Rivian Automotive (RIVN) – Get Rivian Automotive, Inc. Class A Report as the electric vehicle maker confronts severe growing pains and weak fourth-quarter earnings. But Rea…