@Test
    public void noBrowsers() {
        TwaProviderPicker.Action action = TwaProviderPicker.pickProvider(mPackageManager);

        assertEquals(LaunchMode.BROWSER, action.launchMode);
        assertNull(action.provider);
    }
Tests that we attempt don't do anything stupid if the user (somehow) does not have any
browsers on their device.
customtabs/junit/src/android/support/customtabs/trusted/TwaProviderPickerTest.java