Detect rooted devices and send the signal in request headers

[nguyenhuutinh]

Detect rooted devices and report it in SDK request headers

Add RootUtils, a cheap heuristic root check (test-keys build tag, su
binary paths, root manager artifacts) that never spawns a process and
caches its result for the process lifetime.

• Send the outcome as the rooted: yes|no request header alongside the
  other device headers, on both auth and coverage requests.
• Include ROOTED in DeviceUtils.generateHeaderLogs, so it also reaches
  debug logs and SDK error reports.

Root detection is a risk signal only: it can be hidden by Magisk DenyList
and must not be used on its own to allow or deny authentication.