Support routing audio playback to telephony uplink

This change enables phone apps to play audio to the uplink stream
during a call.
This change maks the AUDIO_OUTPUT_FLAG_INCALL_MUSIC_UPLINK flag to be added to the flags that are sent to the HAL when an ongoing call is active, the chosen output device is the TX telephony device, the stream type is music, and the calling app has the MODIFY_PHONE_STATE permission.
For this change to take place, the following changes were made to the signature of getOutputForAttr in IAudioPolicyService:
  1. Add pid (process id) parameter to getOutputForAttr.
  2. Make the flags parameter a pointer so changed value can be
  examined by calling function.

Bug: 69973354.
Test: tested manually.
Change-Id: I74cef3f8b66de6e0e8f87b6235130c2cdf423da7
diff --git a/services/audiopolicy/AudioPolicyInterface.h b/services/audiopolicy/AudioPolicyInterface.h
index 2a8f54d..7f09e9b 100644
--- a/services/audiopolicy/AudioPolicyInterface.h
+++ b/services/audiopolicy/AudioPolicyInterface.h
@@ -116,7 +116,7 @@
                                         audio_stream_type_t *stream,
                                         uid_t uid,
                                         const audio_config_t *config,
-                                        audio_output_flags_t flags,
+                                        audio_output_flags_t *flags,
                                         audio_port_handle_t *selectedDeviceId,
                                         audio_port_handle_t *portId) = 0;
     // indicates to the audio policy manager that the output starts being used by corresponding stream.