CameraITS: change pylab import

It seems like some matplotlib version does not support
"import pylab" so we need to "from matplotlib import pylab"

Test: make -j32 vts && time vts-tradefed run commandAndExit \
vts-camera-its --primary-abi-only
Bug: 31995717
Change-Id: Icc0f1570a8378b37a8c33e17fb21edd2f07547d0
diff --git a/apps/CameraITS/tests/scene1/test_dng_noise_model.py b/apps/CameraITS/tests/scene1/test_dng_noise_model.py
index b7ba0e8..02bce79 100644
--- a/apps/CameraITS/tests/scene1/test_dng_noise_model.py
+++ b/apps/CameraITS/tests/scene1/test_dng_noise_model.py
@@ -17,7 +17,7 @@
 import its.objects
 import its.image
 import os.path
-import pylab
+from matplotlib import pylab
 import matplotlib
 import matplotlib.pyplot