Create symlink for bionic files

This change creates following symlinks for bionic files.

/system/lib/libc.so -> /apex/com.android.runtime/lib/bionic/libc.so
/system/lib/libm.so -> /apex/com.android.runtime/lib/bionic/libm.so
/system/lib/libdl.so -> /apex/com.android.runtime/lib/bionic/libdl.so
/system/bin/linker -> /apex/com.android.runtime/bin/linker
...

This allows us to not have mountpoints under /bionic.

Bug: 125549215
Test: m and inspect the symlinks in the system partition.
Change-Id: I3a58bf4f88c967862dbf06065a1af8fc4700dda3