Remove deprecated service-related APIs (#572)

diff --git a/mobly/controllers/android_device.py b/mobly/controllers/android_device.py
index 095c94a..0070d75 100644
--- a/mobly/controllers/android_device.py
+++ b/mobly/controllers/android_device.py
@@ -27,7 +27,6 @@
 from mobly.controllers.android_device_lib import errors
 from mobly.controllers.android_device_lib import fastboot
 from mobly.controllers.android_device_lib import service_manager
-from mobly.controllers.android_device_lib.services import sl4a_service
 from mobly.controllers.android_device_lib.services import logcat
 from mobly.controllers.android_device_lib.services import snippet_management_service
 
@@ -622,38 +621,6 @@
         self.adb.serial = new_serial
         self.fastboot.serial = new_serial
 
-    def start_services(self, clear_log=True):
-        """.. deprecated:: 1.8
-
-        Use service manager `self.services` instead.
-
-        Starts long running services on the android device, like adb logcat
-        capture.
-        """
-        self.services.start_all()
-
-    def start_adb_logcat(self, clear_log=True):
-        """.. deprecated:: 1.8
-
-        Use `self.services.logcat.start` instead.
-        """
-        self.services.logcat.start()
-
-    def stop_adb_logcat(self):
-        """.. deprecated:: 1.8
-
-        Use `self.services.logcat.stop` instead.
-        """
-        self.services.logcat.stop()
-
-    def stop_services(self):
-        """.. deprecated:: 1.8
-
-        Use service manager `self.services` instead.
-
-        Stops long running services on the Android device."""
-        self.services.stop_all()
-
     @contextlib.contextmanager
     def handle_reboot(self):
         """Properly manage the service life cycle when the device needs to
@@ -854,23 +821,6 @@
         """
         self.services.snippets.remove_snippet_client(name)
 
-    def load_sl4a(self):
-        """.. deprecated:: 1.8
-
-        Directly register with service manager instead:
-        `self.services.register('sl4a', sl4a_service.Sl4aService)`
-
-        Register sl4a_service directly instead.
-
-        Start sl4a service on the Android device.
-
-        Launch sl4a server if not already running, spin up a session on the
-        server, and two connections to this session.
-        """
-        self.log.warning('`load_sl4a` is deprecated and scheduled for removal!'
-                         ' Register sl4a as a service instead.')
-        self.services.register('sl4a', sl4a_service.Sl4aService)
-
     def take_bug_report(self,
                         test_name,
                         begin_time,
diff --git a/tests/mobly/controllers/android_device_test.py b/tests/mobly/controllers/android_device_test.py
index f83c56f..232cddc 100755
--- a/tests/mobly/controllers/android_device_test.py
+++ b/tests/mobly/controllers/android_device_test.py
@@ -524,20 +524,6 @@
     @mock.patch(
         'mobly.controllers.android_device_lib.fastboot.FastbootProxy',
         return_value=mock_android_device.MockFastbootProxy('1'))
-    @mock.patch('mobly.controllers.android_device_lib.sl4a_client.Sl4aClient')
-    @mock.patch('mobly.utils.get_available_host_port')
-    def test_AndroidDevice_load_sl4a(self, MockGetPort, MockSnippetClient,
-                                     MockFastboot, MockAdbProxy):
-        ad = android_device.AndroidDevice(serial='1')
-        ad.load_sl4a()
-        self.assertTrue(hasattr(ad, 'sl4a'))
-
-    @mock.patch(
-        'mobly.controllers.android_device_lib.adb.AdbProxy',
-        return_value=mock_android_device.MockAdbProxy('1'))
-    @mock.patch(
-        'mobly.controllers.android_device_lib.fastboot.FastbootProxy',
-        return_value=mock_android_device.MockFastbootProxy('1'))
     @mock.patch(
         'mobly.controllers.android_device_lib.snippet_client.SnippetClient')
     @mock.patch('mobly.utils.get_available_host_port')
@@ -666,7 +652,7 @@
     def test_AndroidDevice_snippet_cleanup(
             self, MockGetPort, MockSnippetClient, MockFastboot, MockAdbProxy):
         ad = android_device.AndroidDevice(serial='1')
-        ad.start_services()
+        ad.services.start_all()
         ad.load_snippet('snippet', MOCK_SNIPPET_PACKAGE_NAME)
         ad.unload_snippet('snippet')
         self.assertFalse(hasattr(ad, 'snippet'))
@@ -734,7 +720,7 @@
                 self.resume_called = True
 
         ad = android_device.AndroidDevice(serial='1')
-        ad.start_services()
+        ad.services.start_all()
         ad.services.register('mock_service', MockService)
         with ad.handle_usb_disconnect():
             self.assertFalse(ad.services.is_any_alive)