Update loopTimeoutDuration documentation in NNAPI

Bug: 149686804
Test: m
Change-Id: I0096a2fc2e579d39a2d59a605a4217d53a381691
Merged-In: I0096a2fc2e579d39a2d59a605a4217d53a381691
(cherry picked from commit 6a222a3eec395ff4196675b513fa6878916c8395)
2 files changed