Fix getActiveMicrophones vts failure.

As there could be no mic on the device, the active microphones may not
always exist. With currently implementation in qcom hal, we need to
start the stream to have active microphones. In that case, just check
the return value of the call.

Bug: 109787938
Test: vts-tradefed run vts --module VtsHalAudioV4_0Target
Change-Id: Ia9f5160a278d6c788f8f5eb17b8b276fe1d66076
diff --git a/audio/core/4.0/vts/functional/AudioPrimaryHidlHalTest.cpp b/audio/core/4.0/vts/functional/AudioPrimaryHidlHalTest.cpp
index dab9f7c..9be9b12 100644
--- a/audio/core/4.0/vts/functional/AudioPrimaryHidlHalTest.cpp
+++ b/audio/core/4.0/vts/functional/AudioPrimaryHidlHalTest.cpp
@@ -1100,11 +1100,10 @@
 }
 
 TEST_P(InputStreamTest, getActiveMicrophones) {
-    doc::test("Getting active microphones should always succeed");
+    doc::test("Active microphones of a non started stream may not be retrievable");
     hidl_vec<MicrophoneInfo> microphones;
-    ASSERT_OK(device->getMicrophones(returnIn(res, microphones)));
-    ASSERT_OK(res);
-    ASSERT_TRUE(microphones.size() > 0);
+    ASSERT_OK(stream->getActiveMicrophones(returnIn(res, microphones)));
+    ASSERT_RESULT(okOrNotSupported, res);
 }
 
 //////////////////////////////////////////////////////////////////////////////