Revert "[appmgmt] Add tests for register_app and unregister_app syscalls"

This reverts commit 4c1d471a6ac8a93a30447b1eac94f49482f176b9.
Bug: 130560272

Change-Id: I9f887d74afcf10596545c285d1268e19b9d46ba5
22 files changed