Apply the standard system linker config to all of /data.

This is necessary to get the correct APEX namespace setup for apps that
executes binaries from there.

In older releases no linker config applied to binaries in /data, so the
fallback config in /system/bin/linker was used, which basically just looked
up libraries in /system/{lib,lib64}. With the introduction of APEXes that
location no longer contains the complete set of libraries, so this is
necessary to retain functional parity.

Strictly speaking this fallback rule should apply as last resort for a
binary in any location, but the linker does not accept "dir.system = /".

Test: Flash and boot
Test: The app regression in b/128569634
Bug: 128569634
Change-Id: Icfcd66f0a7d8d898618be1b6186bb1111d20d688