Define a new selinux label for DMABUF system heap

Define the label dmabuf_system_heap_device for /dev/dma_heap/system.
This the default DMA-BUF heap that Codec2 will use one ION is
deprecated.
Test: video playback without denials with DMA-BUF heaps enabled
Bug: 168333162

Change-Id: Ief48165cd804bde00e1881a693b5eb44a45b633b
diff --git a/private/file_contexts b/private/file_contexts
index 8fa09bb..6a9507a 100644
--- a/private/file_contexts
+++ b/private/file_contexts
@@ -92,6 +92,7 @@
 /dev/bus/usb(.*)?       u:object_r:usb_device:s0
 /dev/console		u:object_r:console_device:s0
 /dev/cpu_variant:.*     u:object_r:dev_cpu_variant:s0
+/dev/dma_heap/system    u:object_r:dmabuf_system_heap_device:s0
 /dev/device-mapper	u:object_r:dm_device:s0
 /dev/eac		u:object_r:audio_device:s0
 /dev/event-log-tags     u:object_r:runtime_event_log_tags_file:s0