In the mid-2000s, the Motorola RAZR was a pop culture icon. Paris Hilton often posed with a hot pink version of the flip phone, and footballer David Beckham was the face of the brand. Now, you’re more likely to see the Motorola logo on a handset pinned to a police officer’s chest, or in the hands of a paramedic on the scene of an accident. Since Motorola spun out its struggling cellphone business in 2011, the company has returned to its roots as a specialist in critical communications, providing...