Write Soong tests to confirm Sysprop directories

These tests will break if the sysprop output files and directory
paths are changed. At the very least, this is a good warning to
let us know to change other places accordingly, like the Bazel
rule.

Bug: 235131252
Test: tests
Change-Id: I80f037a6e8fe68cdd2042c64175e0d3bd3fefde3