Fix link-type check warning on libSharedSystemUI

There has been a link-type check warning on libSharedSystemUI
the prebuilt lib is built without SDK but the app using it
(Launcher3QuickStep) is built with SDK. Since this effectively prevents
the app from being unbundled, such warning will turn into errors soon.

However, the lib isn't ready to be built with SDK yet. So, in order to
suppress the link-type check warning until then, the prebuilt lib is
added with LOCAL_SDK_VERSION := current.

Bug: 69899800
Bug: 73327733
Test: m -j Launcher3QuickStep is successful and does not show any
link-type check warning

Change-Id: Ifd74bfee8c608e099737bd46569b05f007c1e86b