Remove voe_auto_test and add new tests to cover the missing cases.

BUG=webrtc:4690

Review-Url: https://codereview.webrtc.org/3007383002
Cr-Commit-Position: refs/heads/master@{#19865}
diff --git a/audio/BUILD.gn b/audio/BUILD.gn
index aa33192..04dec03 100644
--- a/audio/BUILD.gn
+++ b/audio/BUILD.gn
@@ -95,6 +95,7 @@
 
     sources = [
       "audio_receive_stream_unittest.cc",
+      "audio_send_stream_tests.cc",
       "audio_send_stream_unittest.cc",
       "audio_state_unittest.cc",
       "time_interval_unittest.cc",