Add AID_SDCARD_R.

Change-Id: I47f650e415e06c0b69790ffefea7f208c910ebd7
diff --git a/adb/adb.c b/adb/adb.c
index 60568f5..001fae1 100644
--- a/adb/adb.c
+++ b/adb/adb.c
@@ -976,13 +976,14 @@
         ** AID_INET to diagnose network issues (netcfg, ping)
         ** AID_GRAPHICS to access the frame buffer
         ** AID_NET_BT and AID_NET_BT_ADMIN to diagnose bluetooth (hcidump)
+        ** AID_SDCARD_R to allow reading from the SD card
         ** AID_SDCARD_RW to allow writing to the SD card
         ** AID_MOUNT to allow unmounting the SD card before rebooting
         ** AID_NET_BW_STATS to read out qtaguid statistics
         */
         gid_t groups[] = { AID_ADB, AID_LOG, AID_INPUT, AID_INET, AID_GRAPHICS,
-                           AID_NET_BT, AID_NET_BT_ADMIN, AID_SDCARD_RW, AID_MOUNT,
-                           AID_NET_BW_STATS };
+                           AID_NET_BT, AID_NET_BT_ADMIN, AID_SDCARD_R, AID_SDCARD_RW,
+                           AID_MOUNT, AID_NET_BW_STATS };
         if (setgroups(sizeof(groups)/sizeof(groups[0]), groups) != 0) {
             exit(1);
         }