Fix issue 1795088       Improve audio routing code

Integrated comments after patch set 1 review.
diff --git a/android/author/android_audio_input.cpp b/android/author/android_audio_input.cpp
index 0ec8c38..5fdfd8f 100644
--- a/android/author/android_audio_input.cpp
+++ b/android/author/android_audio_input.cpp
@@ -1059,10 +1059,11 @@
                         AudioRecord::RECORD_IIR_ENABLE;
 
     LOGV("create AudioRecord %p", this);
-    android::AudioRecord
-            * record = new android::AudioRecord(
+    AudioRecord
+            * record = new AudioRecord(
                     iAudioSource, iAudioSamplingRate,
-                    android::AudioSystem::PCM_16_BIT, iAudioNumChannels,
+                    android::AudioSystem::PCM_16_BIT,
+                    (iAudioNumChannels > 1) ? AudioSystem::CHANNEL_IN_STEREO : AudioSystem::CHANNEL_IN_MONO,
                     4*kBufferSize/iAudioNumChannels/sizeof(int16), flags);
     LOGV("AudioRecord created %p, this %p", record, this);