Copy lsdump files from non-apex variant

This commit refines the logic to pick the lsdump files for reference ABI
dumps.  Before this commit, `findlsdump()` simply use `str_a in str_b`
to check whether module variant name (e.g.
`android_arm_armv7-a-neon_core_shared`) is in the path.  However, this
check also matches the variant for apex modules (e.g.
`android_arm_armv7-a-neon_core_shared_apex.name`).

This commit fixes the problem by splitting each path into path
components and check whether a path component matches with the module
variant name.

Bug: 121986692
Test: development/vndk/tools/header-checker/utils/create_reference_dumps.py
Change-Id: I98f78f460ddeb076f4ca35b7a0d9dcac4a479ae8