[avalanche] Use sane default for the quorum minimum connected stake ratio

Summary:
Similar to D11917, update the last remaining non compatible tests with an option override and make the sane value the default.

Depends on D11917.

Test Plan:

ninja all check-extended

Reviewers: #bitcoin_abc, PiRK, sdulfari

Reviewed By: #bitcoin_abc, PiRK, sdulfari

Subscribers: sdulfari

Differential Revision: https://reviews.bitcoinabc.org/D11918