Add missing isShellUser check

Bug: 160390416
Test: verified command still works from shell

[basilgello: Back-port to 14.1:
 - {ROOT,SHELL}_UID -> Process.{ROOT,SHELL}_UID]
Signed-off-by: Vasyl Gello <vasek.gello@gmail.com>

Change-Id: I23bb06e00f1623e4f27c02d7eb2c0d273b40771b
(cherry picked from commit 03542611)
Merged-In: I23bb06e00f1623e4f27c02d7eb2c0d273b40771b
(cherry picked from commit 5e2931c6)
(cherry picked from commit 4a31000e6072c14608ec1c59321481c8aa330313)