Add symlinks to Soong-installed sh_binary

I3f9928c6d6993c381859b80c335b800b1a9769ee moved sh_binary installation
to Soong, but the Soong install rules didn't include the symlinks.

Bug: 204136549
Test: m checkbuild
Change-Id: I8dd663c7d6a3259b397a11787e0869f32d0530cd