Refactor python to use AndroidMkEntries.

This is to enable consolidating test compatibility suite handling in
Soong's AndroidMk files.

Bug: 170318013
Test: go test soong tests
Test: m nothing and compare soong/Android mk files -- only diffs is that
      lines matching "^LOCAL_SHARED_LIBRARIES := $" are absent
(cherry picked from commit I4922a1c8b0231cd98ebd2bc7257956eb9c0d240c)
Merged-In: I4922a1c8b0231cd98ebd2bc7257956eb9c0d240c
Change-Id: I4922a1c8b0231cd98ebd2bc7257956eb9c0d240c