Add phonon activation logic
Summary:
This adds the logic to check if the phonon upgrade is activated.
This is done prior to the removal of the graviton activation to allow
for adding a new argument that will trigger the next activation.
Test Plan:
ninja check
Reviewers: #bitcoin_abc, deadalnix, markblundeberg, jasonbcox
Reviewed By: #bitcoin_abc, markblundeberg, jasonbcox
Subscribers: jasonbcox
Differential Revision: https://reviews.bitcoinabc.org/D4742