Only analyze the last 500ms of deferred face auth info

To determine whether to defer a face auth help message
when SysUI receives the face auth TIMEOUT.

For face auth that sends 30fps, this will analyze the last
15 frames before the timeout to determine whether to show
deferred messages like "low light".

Test: atest FaceHelpMessageDeferralTest FaceHelpMessageDebouncerTest
Bug: 351863611
Flag: com.android.systemui.face_message_defer_update
Change-Id: I9dc2eed3924f2f47a81dc0e2538fd9ff151b6146