Fix ordered background broadcast API

This API is only intended for a specific use, so do not allow the caller
to pass in other intents and use it for other things.

Bug: 144108192
Test: atest CellBroadcastIntentsTest
Change-Id: Ibf70fdbb419bbb24f2feeffedc0331e31c865a52
Merged-In: Ibf70fdbb419bbb24f2feeffedc0331e31c865a52