must receivers implement TRIGGER, CONNECT, and DISCONNECT?
While technically, an app only needs to accept
ACTION_TRIGGER Intent@s in order to work with the panic framework, @ACTION_CONNECT and
ACTION_DISCONNECT should also be required since they set up the two-directional TOFU trust association between the panic trigger and the receiver. If a panic receiver only implements
ACTION_TRIGGER, it can't set up the TOFU trust association that happens as part of the
ACTION_CONNECT config sequence.
But if an app did not want any user setup, but instead wanted to pin the trusted apps and automatically use them when they are present, then those apps do not need the TOFU stuff.
support apps that accept the TRIGGER but have no CONNECT config
Instead of the TOFU trust from the CONNECT, pinning could be used with only
a TRIGGER Intent.