run-as: Keep supplementary groups.

This broke TCP debugging because processes don't inherit the AID_INET
group.

Bug: 67058466
Test: adb shell run-as com.example.native_activity groups prints "inet".

(cherry picked from commit 8c27e19c1c20f05db9e9e061dffb3aa56d8275b9)

Change-Id: I30bc3152267a2b3ee099bc9f604c017ef33dd685
1 file changed