Allow gpuservice to read tracefs entries

Gpu service needs tracefs access to attach the BPF program
to the gpu_mem_total tracepoint for GPU memory tracking.

Bug: 208892266
Bug: 209513178
Bug: 214061655
Test: adb shell dumpsys gpu --gpumem
Change-Id: I10fd54544bee940313f3987247c1841101a9d03a
Merged-In: I10fd54544bee940313f3987247c1841101a9d03a
diff --git a/services/gpuservice/gpuservice.rc b/services/gpuservice/gpuservice.rc
index 65a5c27..0da8bd3 100644
--- a/services/gpuservice/gpuservice.rc
+++ b/services/gpuservice/gpuservice.rc
@@ -1,4 +1,4 @@
 service gpu /system/bin/gpuservice
     class core
     user gpu_service
-    group graphics
+    group graphics readtracefs