Update test for go modules with mutliple variants

Go modules now generate files into a variant-specific subfolder.
Since that subfolder depends on the host os/arch, don't explicitly
check its value, but instead allow anything there.

Bug: 369916167
Test: m --no-skip-soong-tests
Change-Id: I37e395c866d34f596f0936b720b89c8f9615dcf8