Just in case anyone else needs to transfer an Android phone's contacts to an iPhone, here's the solution:
As discussed above, load the Android phone's Contacts into your Mac's Contacts / Address Book via Gmail.
Next, open Contacts / Address Book on your Mac, click on any single contact to select it, go to Edit > Select All (Command-A) to select all contacts.
Go to File > Export > Export vCard, and then save this file on your Mac desktop.
Send an email to yourself with this file attached.
Open the email on your iPhone and tap the attachment to import the contacts
Oh, and in future, only edit / add to Contacts on your iPhone, not your Mac. If iPhone's Contacts is amended, iCloud will auto update your Mac's - but not vice versa, for some reason :?