audio: add get_active_micropones() function

The Google VTS tests for Android VtsHalAudioV5_0Target(GetMicrophonesTest)
needs to use pointer of function (*get_active_micropones)() which is not
initialized and function in_get_active_microphones() required for initialization
witch is not implemented in tinyhal.

The analysis of the implementation of the audio hal for Qualcomm
(https://android.googlesource.com/platform/hardware/qcom/audio/+/refs/heads/
master/hal/audio_hw.c) and Goldfish
(https://android.googlesource.com/device/generic/goldfish/+/dc18a59%5E%21/)
have been made. The implementation similar to Goldfish(stub) has been chosen as
basic.

Function in_get_active_microphones() was implemented as stub function that will
expand in the future. This function fill array audio_microphone_characteristic_t
with default microphone information.

Signed-off-by: Anton Dehtiarov <anton.dehtiarov@globallogic.com>

audio/audio_hw.c

@@ -2080,6 +2080,14 @@ static int adev_get_microphones(const struct audio_hw_device *dev,
 }
 #endif
 
+#ifdef AUDIO_DEVICE_API_VERSION_5_0
+static int in_get_active_microphones(const struct audio_stream_in *stream,
+                                     struct audio_microphone_characteristic_t *mic_array,
+                                     size_t *mic_count) {
+    return adev_get_microphones(NULL, mic_array, mic_count);
+}
+#endif
+
 /*********************************************************************
  * Stream open and close
  *********************************************************************/
@@ -2222,6 +2230,10 @@ static int adev_open_input_stream(struct audio_hw_device *dev,
 
     in->common.dev = adev;
 
+#ifdef AUDIO_DEVICE_API_VERSION_5_0
+    in->common.stream.get_active_microphones = in_get_active_microphones;
+#endif
+
     devices &= AUDIO_DEVICE_IN_ALL;
     ret = do_init_in_common(&in->common, config, devices);
     if (ret < 0) {