Merge "Add a new cmd to wait for a specific broadcast to be dispatched." into udc-dev

...re/java/com/android/server/am/ActivityManagerService.java

...va/com/android/server/am/ActivityManagerShellCommand.java

.../core/java/com/android/server/am/BroadcastDispatcher.java

...ore/java/com/android/server/am/BroadcastProcessQueue.java

services/core/java/com/android/server/am/BroadcastQueue.java

...s/core/java/com/android/server/am/BroadcastQueueImpl.java

.../java/com/android/server/am/BroadcastQueueModernImpl.java

...c/com/android/server/am/BroadcastQueueModernImplTest.java

...estests/src/com/android/server/am/BroadcastQueueTest.java