modify cc_binary type to cc_test for test modules

1. When a cc_binary type module has the non-empty test_suites field,
modify the type to cc_test;
2. Unit tests were also added.

Bug: 193071602
Test: m androidmk
Test: TreeHugger
Change-Id: Icfaa79998616c02bb086f81d194163feafb4c116