audio flinger: add suffix to time variables names

Add suffix to clarify units for the following variables:
 standbyTime -> mStandbyTimeNs
 standbyDelay -> mStandbyDelayNs
 activeSleepTime -> mActiveSleepTimeUs
 idleSleepTime -> mIdleSleepTimeUs
 sleepTime -> mSleepTimeUs

Change-Id: I7f5d602c39e0ef3f6fe9ef99eaf1b351c7bd4fc3
2 files changed