allow_all_shared_libs for media namespace in ld.config.legacy.txt

This is a temporal fix. With this change, the extractor plug-ins uses
unstable libs under /system/lib[64]. The right resolution is being
discussed.

Test: applied the same change to ld.config.txt and checked
      the memory map of media.extractor on cuttlefish.
Bug: 127791685

Change-Id: Ifd5b79831f27ef4017bb8aa774671aa9b2c5264e