flounder: sensor_hub: Add retry mechanism for IIO trigger

We encounter libart crash in EStress test.
When libart crashes, system_server will restart,
and SensorHAL constructor will be called, at this moment,
IIO trigger device node is busy.

In order to make SensorHAL more robust, add logs when error and
try to enable IIO current_trigger while we needs IIO channel.

Change-Id: Ic8a4e285cfe11535663e6a8dfcc8daf694aa01c1
2 files changed