audio policy: session routes continued.

- Clear session routes when client process dies.
- Enforce the route only when the requesting session is active.
- Fix requested route not working if an output mix change is required
(e.g forcing to SPEAKER when the default route is USB or A2DP).
- Make sure all sessions sharing the strategy with a rerouted session
have the same route (needed for volume control consistency)

Change-Id: I0ab347a8fb97e73e2c5965374544c5f4fe509ef1
diff --git a/media/libmedia/AudioSystem.cpp b/media/libmedia/AudioSystem.cpp
index 3478441..12cd257 100644
--- a/media/libmedia/AudioSystem.cpp
+++ b/media/libmedia/AudioSystem.cpp
@@ -653,6 +653,7 @@
                                         audio_io_handle_t *output,
                                         audio_session_t session,
                                         audio_stream_type_t *stream,
+                                        uid_t uid,
                                         uint32_t samplingRate,
                                         audio_format_t format,
                                         audio_channel_mask_t channelMask,
@@ -662,7 +663,7 @@
 {
     const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
     if (aps == 0) return NO_INIT;
-    return aps->getOutputForAttr(attr, output, session, stream,
+    return aps->getOutputForAttr(attr, output, session, stream, uid,
                                  samplingRate, format, channelMask,
                                  flags, selectedDeviceId, offloadInfo);
 }
@@ -697,6 +698,7 @@
 status_t AudioSystem::getInputForAttr(const audio_attributes_t *attr,
                                 audio_io_handle_t *input,
                                 audio_session_t session,
+                                uid_t uid,
                                 uint32_t samplingRate,
                                 audio_format_t format,
                                 audio_channel_mask_t channelMask,
@@ -706,7 +708,7 @@
     const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
     if (aps == 0) return NO_INIT;
     return aps->getInputForAttr(
-            attr, input, session, samplingRate, format, channelMask, flags, selectedDeviceId);
+            attr, input, session, uid, samplingRate, format, channelMask, flags, selectedDeviceId);
 }
 
 status_t AudioSystem::startInput(audio_io_handle_t input,