Merge "Assert and verify setting system property in UserManagerServiceTest."

import static android.os.UserManager.DISALLOW_USER_SWITCH;

import static com.google.common.truth.Truth.assertThat;

import static com.google.common.truth.Truth.assertWithMessage;

import android.app.ActivityManager;

import android.app.PropertyInvalidatedCache;

import android.os.FileUtils;

import android.os.Looper;

import android.os.Parcelable;

import android.os.SystemProperties;

import android.os.UserHandle;

import android.os.UserManager;

import android.platform.test.annotations.Postsubmit;

    private static String setSystemProperty(String name, String value) throws Exception {

        final String oldValue = runShellCommand("getprop " + name);

        assertThat(runShellCommand("setprop " + name + " " + value))

                .isEqualTo("");

        assertWithMessage("can not set system property")

                .that(runShellCommand("setprop " + name + " " + value)).isEqualTo("");

        assertWithMessage("failed to set system property")

                .that(SystemProperties.get(name)).isEqualTo(value);

        return oldValue;

    }