ANDROID: define python library in BUILD for kunit parser

This library is used by kunit tests define using the kunit_test Kleaf rule.

This cherry-pick is manually edited to remove `py_library` import since this branch doesn't have complete starlarkification of Bazel.

Bug: 408445790
Change-Id: I524b9be5aeb350195e9ed0185442c9caabe48976
Signed-off-by: Sid Nayyar <sidnayyar@google.com>