Indy has far too many references to Earth specific events and objects to be a coincidence. The World Wars, The Ark of the Covenant, Nazis, Harvard University, Venice, planes, automobiles, trains, rifles, pistols, swords, whips...
The maps in the movie also show pretty clearly that they are on earth. The maps are quite iconic although I can't seem to find a sample image at the moment.
For another planet in another galaxy to have a planet with the same layout of continents, with the same countries with the same cities with the same names, with the same technology and the same universities and the same religions...it's all a bit much.
As for the references to star wars characters, it is either a coincidence and we are mistaking the hieroglyphs for looking like those characters when they are something else, such as a guy in a type of armor and some kind of false idol/utility -- or those characters (or similar models) somehow made it to visit the ancient civilizations that made those hieroglyphs, through an adventure we have not yet seen.