audio policy: fix isSourceActive() for hotword

Only condider AUDIO_SOURCE_HOTWORD equivalent to
AUDIO_SOURCE_VOICE_RECOGNITION if the active capture
was triggered by a hardware hotword recognition.

Also fix activeInputsCount().

Bug: 18802896.
Change-Id: I471aafcae29a76e9c323c6c0c314ef083991476b
1 file changed