On userdebug & eng builds, change the owner/group of SJTAG sysfs files
that need to be written to 'system'. This became necessary after these
files were migrated out of DebugFS, as write access to the world is no
longer supported.
Bug: 188817349
Test: Ensure that the writable files in the following directories have
'system' as their owner & group:
/sys/devices/platform/sjtag_ap/interface/
/sys/devices/platform/sjtag_gsa/interface/
Signed-off-by: Peter Csaszar <pcsaszar@google.com>
Change-Id: I4420fccd92522a48f44b80bd0a19f4a20eb32442
9cd8c6e58f