docs: Added a missing "be" in ACTION_CONNECTION_STATE_CHANGED

Status: Ready for writer review.
Note: This is a javadoc only change.

Test: Build the docs with "make ds-docs" and staged updated content.
Staged content:
go/dac-stage/reference/android/bluetooth/BluetoothAdapter.html#ACTION_CONNECTION_STATE_CHANGED

Bug: 69097875
Change-Id: Ibffea2373ded825558beaa669ae4daf3c0ff3d2f