This is to differentiate soong intermediate directories for soong config
modules. This will help incremental build across different
devices.

Test result of building panther, building cheetah, and building panther
again:

Before this change
- build time: 02:57
- # of tasks: 31044

After this change
- build time: 01:48
- # of tasks: 1694

Build time includes build.ninja generating time (which is more than 1
minute), so the overriden artifacts become far fewer.

And "NINJA_ARGS='-n -d explain' m" only gave 4 "command line changed"
nodes.

Bug: 279362051
Test: see above
Change-Id: I4891cbe823ae21628465e5c6eb26a4837ccdd202