Change wallet 'send' button to 'next'

[rachelhamlin]

Problem
The 'Send' button in the wallet generated Tx flow leads to the Tx overview, where you can edit network fee and check details.

Let's change the button that leads to this screen from 'Send' to 'Next', so users know there is another step in the process. Otherwise they may worry they are signing the Tx without review.

Screenshot:

Acceptance Criteria:

• Use the 'next' label for the bottom sheet, rather than the send button.