Cleanup "Use of an assertion within an except block is error-prone [g-assert-in-except]"

[johnklee]

Tracker bug for cleaning up "Use of an assertion within an except block is error-prone [g-assert-in-except]":

    try:
      raise android_device.DeviceError(ad, 'Something')
    except android_device.DeviceError as e:
      self.assertEqual('<AndroidDevice|1> Something', str(e))

Should be:

    with self.assertRaisesRegex(android_device.DeviceError,
                                '<AndroidDevice|1> Something'):
      raise android_device.DeviceError(ad, 'Something')

Linting warning found:

C6903:1147:AndroidDeviceTest.test_AndroidDevice_debug_tag: Use of an assertion within an except block is error-prone [g-assert-in-except]
http://go/gpylint-faq#g-assert-in-except
C6903:1153:AndroidDeviceTest.test_AndroidDevice_debug_tag: Use of an assertion within an except block is error-prone [g-assert-in-except]
http://go/gpylint-faq#g-assert-in-except
W0703:1157:AndroidDeviceTest.test_AndroidDevice_debug_tag: Catching too general exception Exception [broad-except]
--
C6903:1158:AndroidDeviceTest.test_AndroidDevice_debug_tag: Use of an assertion within an except block is error-prone [g-assert-in-except]
http://go/gpylint-faq#g-assert-in-except