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: f3aed605 am: 1ceb089e
Change-Id: I7343922af39e239bba63100078116b3be19f329a