Revert "Revert "Adding new constants for STEP_DETECTOR, STEP_COUNTER and GEOMAGNETIC_ROTATION_VECTOR.""

This reverts commit 042146d2fec91687204bb0322f0aa826578807d6.
Revert "Revert "Fix for build breakage. Correcting the documentatation link in Sensor.java. I added a wrong link {@link #SENSOR_TYPE_ROTATION_VECTOR} instead of {@link #TYPE_ROTATION_VECTOR}.""

This reverts commit 3eb42ce5ee6b2a5a6680a88a280585030caafe34.
Revert "Revert "Sensor batching. Implementation for registerListener(with batch support) and flush APIs.""

This reverts commit baf1736ac53c3cb8adf4ff977694202125785e26.
Revert "Revert "Fix for build breakage. Remove documentation link to hidden registerListener API.""

This reverts commit 6eff689aa8eea76e0346c28c529c51d1d9ed665b.
Revert "Revert "Sensor batching APIs for review.""

This reverts commit 14178264b77d4d530e47d851ac7a5419b39510ea.
Revert "Revert "Fix registerListener and flush bugs.""

This reverts commit 43d6dfc1d46088a9bb5f104aa30c69fad3e168d2.
Update README