Send CMAS broadcast to additional package

This is for sl4a automation to receive CMAS messages
broadcasdt. The automation should inject the settings
through 'adb settings'.

Test: manual
bug: 34393649
Merged-In: I88b0a568183b9701712e5071a6692e5d1ce08c7d
Change-Id: I88b0a568183b9701712e5071a6692e5d1ce08c7d