Update Java doc of SensorManager.createDirectChannel

Java doc was left out when addressing API reviewer comments.
This CL fix the discrepancy between the actual logic and java doc.

Bug: 36550285
Test: compiles
Change-Id: I6406892ecdcc5d02f11966fa3fb0b81ed8d3b285
Merged-In: I6406892ecdcc5d02f11966fa3fb0b81ed8d3b285
1 file changed