Merge "Fix EthernetTetheringTest failure if tethering is not supported"

    private UiAutomation mUiAutomation =

            InstrumentationRegistry.getInstrumentation().getUiAutomation();

    private boolean mRunTests;

    @Before

    public void setUp() throws Exception {

        mHandlerThread = new HandlerThread(getClass().getSimpleName());

        mHandlerThread.start();

        mHandler = new Handler(mHandlerThread.getLooper());

        mTetheredInterfaceRequester = new TetheredInterfaceRequester(mHandler, mEm);

        // Needed to create a TestNetworkInterface, to call requestTetheredInterface, and to receive

        // tethered client callbacks.

        mUiAutomation.adoptShellPermissionIdentity(

                MANAGE_TEST_NETWORKS, NETWORK_SETTINGS, TETHER_PRIVILEGED);

        mRunTests = mTm.isTetheringSupported() && mEm != null;

        assumeTrue(mRunTests);

        mHandlerThread = new HandlerThread(getClass().getSimpleName());

        mHandlerThread.start();

        mHandler = new Handler(mHandlerThread.getLooper());

        mTetheredInterfaceRequester = new TetheredInterfaceRequester(mHandler, mEm);

    }

    private void cleanUp() throws Exception {

    @After

    public void tearDown() throws Exception {

        try {

            cleanUp();

            if (mRunTests) cleanUp();

        } finally {

            mUiAutomation.dropShellPermissionIdentity();

        }