Log exception info when failing to provision a device

BUG=429248

Review URL: https://codereview.chromium.org/703643003

Cr-Commit-Position: refs/heads/master@{#302725}

build/android/provision_devices.py

@@ -207,7 +207,7 @@ def ProvisionDevice(device, options, is_perf):
     # Device black list is reset by bb_device_status_check.py per build.
     device_blacklist.ExtendBlacklist([str(device)])
   except (device_errors.CommandFailedError):
-    logging.info('Failed to provision device %s. Adding to blacklist.',
+    logging.exception('Failed to provision device %s. Adding to blacklist.',
                       str(device))
     device_blacklist.ExtendBlacklist([str(device)])