This patch supports basic filtering of log lines from physical iOS
devices, similar to existing functionality for iOS simulator logging.

This patch also suppresses the following two log messages which are
emitted at app startup on iOS 10.3 devices:
  libMobileGestalt MobileGestaltSupport.m:153: pid 123 (Runner) does not have sandbox access for frZQaeyWLUvLjeuEK43hmg and IS NOT appropriately entitled
  libMobileGestalt MobileGestalt.c:550: no access to InverseDeviceID (see <rdar://problem/11744455>)