My significant other is from Hawaii, and says everyone over there, the natives included, pronounce it "Ka-may-uh-may-uh" (no h sounds), and also that the Hulihee Palace is pronounced "Hu-lah-ay-ay" again, no h sounds on h's that come after the first syllable.

Since this is coming from someone who still regularly speaks to their Native Hawaiian friends and lived there for fifteen years, and is quite fluent in the language, I assume it's correct.

But you know, grain of salt, etc.