Adds context_hub group to pixel stats

Bug: 149981913
Test: Flash, verify can connect to CHRE daemon
Change-Id: I06411b111a11a055a73680e56b3ea5930e7043c3
diff --git a/pixelstats/pixelstats-vendor.crosshatch.rc b/pixelstats/pixelstats-vendor.crosshatch.rc
index 9410090..22254bb 100644
--- a/pixelstats/pixelstats-vendor.crosshatch.rc
+++ b/pixelstats/pixelstats-vendor.crosshatch.rc
@@ -1,4 +1,4 @@
 service vendor.pixelstats_vendor /vendor/bin/pixelstats-vendor
     class hal
     user system
-    group system
+    group system context_hub