Revert "Use proguard version 6.0.3 for monochrome_public_apk."

This reverts commit df22b81425e5487282a2569f9fd274300a43e3e5.

Reason for revert: breaks generate_build_files (http://crbug.com/869231)

Original change's description:
> Use proguard version 6.0.3 for monochrome_public_apk.
> 
> MonochromePublic.apk release builds are very close to the main dex limit
> and updating proguard reduces the number of methods by about 3000.
> 
> 6.0.3 cannot be used for all APKs yet due to a bug which causes
> cronet_test_instrumentation_apk to fail.
> 
> The version mismatch should be temporary as we plan to switch to R8 in the
> future (https://crbug.com/868770).
> 
> Bug: 857572
> Cq-Include-Trybots: master.tryserver.chromium.android:android_cronet_tester
> Change-Id: I3676a42908c5046dc3f3831e282150702038140d
> Reviewed-on: https://chromium-review.googlesource.com/1154366
> Reviewed-by: Yaron Friedman <yfriedman@chromium.org>
> Commit-Queue: Eric Stevenson <estevenson@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#579250}

TBR=yfriedman@chromium.org,estevenson@chromium.org

Change-Id: I1d7e50cf720e9a128a62f06bb34a4c9f6d25c60d
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 857572
Bug: 869231
Cq-Include-Trybots: master.tryserver.chromium.android:android_cronet_tester
Reviewed-on: https://chromium-review.googlesource.com/1155502
Reviewed-by: Nate Fischer <ntfschr@chromium.org>
Commit-Queue: Nate Fischer <ntfschr@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#579262}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: fb3a9711abe92f1e08611430bd619fd9ff20628e
2 files changed
tree: e026022b0e2b074fe46644f0c99f09773fd33a43
  1. lib/
  2. BUILD.gn
  3. LICENSE
  4. OWNERS
  5. README.chromium