hal: Update STHAL about Voicecall usecase.

SVA detetions are happening during voice call in progress.
Because STHAL is not updated about the voice call usecase and hence SVA is
not being paused.

Fix this issue by sending callback to STHAL from AHAL.

Change-Id: I441aeec56fae5bcfbab3eed6697f08e6901024e6
diff --git a/hal/audio_extn/soundtrigger.c b/hal/audio_extn/soundtrigger.c
index c49d779..b0478c0 100644
--- a/hal/audio_extn/soundtrigger.c
+++ b/hal/audio_extn/soundtrigger.c
@@ -512,7 +512,7 @@
                 ALOGW("%s:invalid event %d, for usecase %d",
                                       __func__, event, uc_info->id);
             }
-        } else if (uc_info->type == PCM_CAPTURE) {
+        } else if ((uc_info->type == PCM_CAPTURE) || (uc_info->type == VOICE_CALL)) {
             if (event == ST_EVENT_STREAM_BUSY)
                 ev = AUDIO_EVENT_CAPTURE_STREAM_ACTIVE;
             else