Temporarily reverting change Ifbeae7e9 for 2 weeks to allow time to
fix issues with TimedMediaHandler and other extensions.

This will temporarily allow HTML in JS i18n strings again.

See related bugs 44977, 44525, 44885, 43512

OKed by Krinkle.

Change-Id: Iedb304f80b79bb65b9080909a1d70d432ee8aa5d
Merge "Temporarily reverting change Ifbeae7e9 for 2 weeks to allow time to fix issues with TimedMediaHandler and other extensions."