Fix Quiescent Reboot Reason

[Description]
Revise system property "sys.powerctl" when the reason is quiescent.
When the reason is only quiescent,
the value of the system property "sys.powerctl"
should be "reboot,quiescent" instead of "reboot,,quiescent".

Bug: 192634025

Test:
adb shell svc power reboot quiescent

Change-Id: I9b3ac851f85fac093c4767f5bc82baa07181dda5
1 file changed