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: df77eb4a am: 1e4b7bff
Change-Id: Ie682dca9665e6c8eab56b65dc6264ac441d0cad2