sepolicy: allow audioserver to use ALSA MMAP FDs

Bug: 37504387
Test: aaudio example write_sine, needs MMAP support
Change-Id: I7fbd87ad4803e8edbde4ba79220cb5c0bd6e85a0
Signed-off-by: Phil Burk <philburk@google.com>

private/audioserver.te

@@ -39,6 +39,9 @@ allow audioserver scheduling_policy_service:service_manager find;
 allow audioserver audio_data_file:dir ra_dir_perms;
 allow audioserver audio_data_file:file create_file_perms;
 
+# allow access to ALSA MMAP FDs for AAudio API
+allow audioserver audio_device:chr_file { read write };
+
 ###
 ### neverallow rules
 ###