ReadAloud stops on Chrome Android when screen off

**Description**

> What problem are we solving? What does the experience look like today? What are the symptoms? How can one reproduce the problem?

**Evidence / Screenshot (if possible)**

> Include evidence of the problem or provide a screenshot.

**Expectation**

> What should be happening? What will it look like / how will it behave when fixed?

**Context**

> What operating system? What browser type and version?

**Proposal & Constraints**

> What is the proposed solution / implementation? Is there a precedent of this approach succeeding elsewhere?

**Stakeholders**

@mekarpeles