/usr/share/php7.0-interbase/interbase/pdo_firebird.ini is in php7.0-interbase 7.0.4-7ubuntu2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 | ; configuration for php interbase module
; priority=20
extension=pdo_firebird.so
|