Merge "Document that some Telecom broadcast and extra keys are dead-ends."...
Merge "Document that some Telecom broadcast and extra keys are dead-ends." into rvc-dev am: f7643e91 am: 7283b11a am: 4587039a am: 140f7bb2
Change-Id: I15c38fda03383f51f383013ace2e87cf7ad550ae