AIDEGen: Fix case that get_unique_iml_name() failed to create unique iml name.

Some test apps have duplicated physical path, which causes duplicated iml name
happened, so, use following strategy to generate unique iml name :
1. Using unique module path string to generate iml name.
2. Appending sequence number to iml name when two modules still have same name.

Bug: 133393638
Test: 1. $ atest aidegen_unittests --host will get pass result.
Change-Id: I99eeaf30fa99a13e50b80400a0a145bbe7f284af