handover_test prep: rename 'create-bts' to 'create-n-bts'

I will add a command to create a single BTS with arbitrary timeslot
configurations.

To limit amount of editing of the current tests, keep the current 'create-bts'
command, which creates N identically configured BTS, but rename it to
'create-n-bts'.

Thus allow the upcoming single-BTS command to take the name 'create-bts'.

Change-Id: I4853771cf23b509b7f278d04c57883332ede786d
1 file changed