The bt-rfcomm component exposes a testonly capability: fuchsia.bluetooth.rfcomm.test.RfcommTest. This capability should only be used in test configurations.
By default, this capability is not exposed to the system. In order to expose it, update the build:
Add the core-testonly Bluetooth group to the set of base packages in core.gni. e.g. Replace //src/connectivity/bluetooth:core with //src/connectivity/bluetooth:core-testonly.
Add the bt-init testing shard to the group of core_realm_shards. This allows v1 components (e.g SL4F, BT-tools) to access the RfcommTest capability.
Update the bluetooth-core realm in core.cml to point to "fuchsia-pkg://fuchsia.com/bt-init-testonly#meta/bt-init-testonly.cm". This constructs the bluetooth-core realm with the testonly capability routes.