runtest --path fails with symlinked ANDROID_BUILD_TOP

While reproducing b/2558977 I found that "runtest --path" did not work
for me because my ANDROID_BUILD_TOP contained a symlink. This is a
local fix to make FindTests use os.path.realpath instead of only half
using os.path.abspath when trying to make canonical paths to compare.

Change-Id: Ief353f52cb80b1798edc3c1233d1e082d9cebc26
1 file changed