Merge changes I6a6cffde,I5789305a,I2c2e15be,Ic1ef7c77,Ic62aa869

* changes:
  Avoid automatically closing of persistent ContextHubClients
  Implements updated PendingIntent APIs
  Refactors ContextHubClientManager/Broker classes
  Only send messages to CHRE if client is registered
  Updates PendingIntent-based service APIs