EffectBundle: check nb channels to write speaker angles

When speaker angles are queried, the size of the array for the
  returned data is 3x the number of channels (where really it
  should be max(2, nbChannels)). The code assumed it was at
  least 3x2 (where 2 is the number of virtual speakers this
  effect supports) and would thus crash when called for a mono
  channel mask.

Test: see repro steps in bug
Bug: 32591350
Change-Id: I33d4bff6b2e19a9fc4284a85a446804878d3a410
diff --git a/media/libeffects/lvm/wrapper/Bundle/EffectBundle.cpp b/media/libeffects/lvm/wrapper/Bundle/EffectBundle.cpp
index 4153a6b..f0091d8 100644
--- a/media/libeffects/lvm/wrapper/Bundle/EffectBundle.cpp
+++ b/media/libeffects/lvm/wrapper/Bundle/EffectBundle.cpp
@@ -1301,17 +1301,25 @@
 //                            horizontal plane, +90 is directly above the user, -90 below
 //
 //----------------------------------------------------------------------------
-void VirtualizerGetSpeakerAngles(audio_channel_mask_t channelMask __unused,
+void VirtualizerGetSpeakerAngles(audio_channel_mask_t channelMask,
         audio_devices_t deviceType __unused, int32_t *pSpeakerAngles) {
     // the channel count is guaranteed to be 1 or 2
     // the device is guaranteed to be of type headphone
-    // this virtualizer is always 2in with speakers at -90 and 90deg of azimuth, 0deg of elevation
-    *pSpeakerAngles++ = (int32_t) AUDIO_CHANNEL_OUT_FRONT_LEFT;
-    *pSpeakerAngles++ = -90; // azimuth
-    *pSpeakerAngles++ = 0;   // elevation
-    *pSpeakerAngles++ = (int32_t) AUDIO_CHANNEL_OUT_FRONT_RIGHT;
-    *pSpeakerAngles++ = 90;  // azimuth
-    *pSpeakerAngles   = 0;   // elevation
+    // this virtualizer is always using 2 virtual speakers at -90 and 90deg of azimuth, 0deg of
+    // elevation but the return information is sized for nbChannels * 3, so we have to consider
+    // the (false here) case of a single channel, and return only 3 fields.
+    if (audio_channel_count_from_out_mask(channelMask) == 1) {
+        *pSpeakerAngles++ = (int32_t) AUDIO_CHANNEL_OUT_MONO; // same as FRONT_LEFT
+        *pSpeakerAngles++ = 0; // azimuth
+        *pSpeakerAngles = 0; // elevation
+    } else {
+        *pSpeakerAngles++ = (int32_t) AUDIO_CHANNEL_OUT_FRONT_LEFT;
+        *pSpeakerAngles++ = -90; // azimuth
+        *pSpeakerAngles++ = 0;   // elevation
+        *pSpeakerAngles++ = (int32_t) AUDIO_CHANNEL_OUT_FRONT_RIGHT;
+        *pSpeakerAngles++ = 90;  // azimuth
+        *pSpeakerAngles   = 0;   // elevation
+    }
 }
 
 //----------------------------------------------------------------------------