Fix profile saver to use base dex location

Previously we were using the dex location. This only matches the
base location for the main dex file, and resulted in only the
main dex file to have classes recorded.

Bug: 28463739

(cherry picked from commit 9275af6e)

Change-Id: Ie822c2a38fd1316c3ba604b8625c48388f6a8c07