Support multiple detectors in VoiceInteractionManagerService

It is possible the Assistant application would like to have
multiple detectors to support different quick phrases at a
given time.

Currently, there is a limitation that only a single detector can
be active at a given time. So we need to change the logic to
support multiple detectors in framework voice interaction, but
all detectors will use the same trusted hotword service.

For multiple detector, we only support one Dsp trusted hotword
detector and one software hotword detector at the same time.

Test: atest CtsVoiceInteractionTestCases
Bug: 193232191
Bug: 243598246
Change-Id: Iee37fbd05d39d8bece685276e59989327ac4c2d1