要在Android Espresso测试中授予权限，可以使用Espresso Intents库和Mockito库。下面是一个示例解决方法：

首先，确保在你的项目中添加以下依赖项：

androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'
androidTestImplementation 'androidx.test.espresso:espresso-intents:3.4.0'
androidTestImplementation 'androidx.test.espresso:espresso-contrib:3.4.0'
androidTestImplementation 'org.mockito:mockito-core:3.11.2'

接下来，在你的测试类中，添加以下import语句：

import static androidx.test.espresso.intent.Intents.intended;
import static androidx.test.espresso.intent.matcher.IntentMatchers.hasAction;
import static androidx.test.espresso.intent.matcher.IntentMatchers.toPackage;
import static androidx.test.espresso.intent.matcher.IntentMatchers.hasCategories;
import static androidx.test.espresso.intent.matcher.IntentMatchers.hasComponent;
import static androidx.test.espresso.intent.matcher.IntentMatchers.hasExtraWithKey;
import static androidx.test.espresso.intent.matcher.IntentMatchers.hasData;
import static androidx.test.espresso.intent.matcher.IntentMatchers.hasComponentClassName;
import static androidx.test.espresso.intent.matcher.IntentMatchers.hasPackage;
import static androidx.test.espresso.intent.matcher.IntentMatchers.hasType;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;
import static org.mockito.ArgumentMatchers.any;

import androidx.test.espresso.intent.rule.IntentsTestRule;
import androidx.test.espresso.intent.Intents;
import androidx.test.espresso.intent.matcher.IntentMatchers;

import org.junit.After;
import org.junit.Before;
import org.junit.Rule;
import org.junit.Test;

接下来，创建一个测试类，并在其中添加以下代码：

public class MyTest {

    @Rule
    public IntentsTestRule mActivityRule = new IntentsTestRule<>(MainActivity.class);

    @Before
    public void setup() {
        // 授予权限
        PackageManager packageManager = mock(PackageManager.class);
        when(packageManager.checkPermission(any(String.class), any(String.class))).thenReturn(PackageManager.PERMISSION_GRANTED);
        mActivityRule.getActivity().setPackageManager(packageManager);
    }

    @After
    public void tearDown() {
        // 清除授权
        Intents.release();
    }

    @Test
    public void testPermissionGranted() {
        // 在这里执行测试逻辑，例如点击按钮触发权限请求
        onView(withId(R.id.button)).perform(click());

        // 验证权限请求是否被授予
        intended(allOf(
                toPackage("com.your.package.name"),
                hasAction(android.provider.Settings.ACTION_APPLICATION_DETAILS_SETTINGS),
                hasData(Uri.parse("package:" + mActivityRule.getActivity().getPackageName()))
        ));
    }
}

在上面的示例代码中，我们使用Mockito库模拟了PackageManager类，并将所需的权限设置为已授予。然后，在测试方法中，我们使用Espresso的intended()方法和IntentMatchers来验证是否正确地启动了权限请求。