openharmony-standard_3.0: install system haps in /system/app directory

In OpenHarmony system applications HAP packages such as Launcher, SystemUI, Settings are located under /system/app directory. These packages are automatically installed and started at system initialization. These system apps are treated differently from third party applications that can be installed using hdc install, for example they have a different UID range and different permissions (they cannot be uninstalled).

This fixes testcases ActsBundleManagerTest::getBundleInfo_1300 and ActsBundleManagerUninstallTest::uninstall_0600

Relate-to: https://gitlab.eclipse.org/eclipse/oniro-core/meta-openharmony/-/issues/21

Signed-off-by: Francesco Pham francesco.pham@huawei.com