[Python] Bug when using bool arrays with stride greater than 1

>>> import numpy as np
>>> import pyarrow as pa
>>> pa.__version__
'0.14.0'
>>> xs = np.array([True, False, False, True, True, False, True, True, True, False, False, False, False, False, True, False, True, True, True, True, True])
>>> xs_sliced = xs[0::2]
>>> xs_sliced
array([ True, False, True, True, True, False, False, True, True,
 True, True])
>>> pa_xs = pa.array(xs_sliced, pa.bool_())
>>> pa_xs
<pyarrow.lib.BooleanArray object at 0x00000234C5165360>
[
 true,
 false,
 false,
 false,
 false,
 false,
 false,
 false,
 false,
 false,
 false
]