Erlotinib Completed Phase 2 Trials for Unresectable Extrahepatic Bile Duct Carcinoma / Unresectable Gallbladder Carcinoma / Gallbladder Adenocarcinoma With Squamous Metaplasia / Recurrent Extrahepatic Bile Duct Carcinoma / Extrahepatic Bile Duct Adenocarcinoma / Recurrent Gallbladder Carcinoma / Hilar Cholangiocarcinoma / Gallbladder Adenocarcinoma / Undifferentiated Gallbladder Carcinoma Treatment