Allow dlopen("/system/lib/<soname>") for pre-Q

It's enabled for the following .so libraries
libicuuc.so
libicui18n.so

This CL does not move the .so files into a APEX.
Thus, no visible effect before moving .so files.

Bug: 121248172
Test: Perform the following test after moving libicuuc to /apex
      dlopen("/system/lib64/libicuuc.so") for targetSdkVersion < Q
Change-Id: Ic00d281d59de924c01582c48d2a946e3f5f33a09