allow surfaceflinger to use socket from adbd

Fixes `adb shell cmd gpu vkjson`, which was previously failing due to
surfaceflinger not being able to use the socket passed to it by adbd.

Bug: b/37157136
Test: run above command, verified on marlin + bullhead
Change-Id: I57fa7e99d5c3dc7bc7d033b83f8ce6032162d7d3