By Dawn Chmielewski and Lisa Richwine (Reuters) – Walt Disney Co said on Tuesday its marquee streaming service, Disney+, gained more subscribers than Wall Street had expected, but investment costs dragged quarterly earnings below analysts’ targets. Shares in Disney fell 5% in after-market trading. The entertainment company is spending billions to compete with Netflix Inc and others for streaming television customers as traditional TV declines in popularity. Disney+ reported 164.2 million subscribers in the fiscal fourth quarter, surpassing Factset estimates of 161 million. The cost to build Di…