Fix button activation on validated fields.
Added non-null validation for public key field and ensure that both field validation is satisfied before activating button.
Trigger keyup event on public key textarea to activate button when file is chosen and textarea is populated with its contents.
Same fix needed for the 'create' dialog.
Merge branch 'EUCA-6528' into maint/3.3/testing

Conflicts:
	console/static/js/keypair.js