Redirect /system/lib/libicuuc.so regardless of duplication in /system

The change is a workaround of app compat issue until the app fixes the
issue.

Likely, the app does not only dlopen(), but open() the libicuuc.so
with the absolute path.

Note that platform uses the stub libandroidicu.so, not libicuuc directly.
This CL topic moves (not duplicates) libandroidicu from /system to
/apex. Even though /system/lib/libicuuc.so is kept in the default
namespace, but no one should be using it.

Some debug info after this CL:
$ adb shell cat /proc/<zygote pid>/maps | grep libicuuc
$ adb shell cat /proc/<app pid>/maps | grep libicuuc
Only /apex/com.android.runtime/lib64/libicuuc.so is found, not the
/system.

Bug: 124218500
Test: The app can be launched successfully
Test: CtsJniTestCases
Change-Id: I67a50f0ad934be567a63d4038215546c9b4e5f7e