[android] Make main_dex_list.py use the same proguard as everything else.

Realized that main_dex_list was using a different version of proguard
while working on test multidex.

Review-Url: https://codereview.chromium.org/2840533003
Cr-Original-Commit-Position: refs/heads/master@{#466733}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 55fc2829afb24aa310dde477d64d07d35a32e46e
1 file changed