Merge pull request #19115 from etiennesegonzac/bug-999356

Bug 999356 - Making sure we don't get kill when initially displaying a USSD message r=gsvelto
(cherry picked from commit cad08e4e4380f3179e611c0c094baf92c8f36e90)

Conflicts:
	apps/communications/dialer/test/unit/dialer_test.js