Revert "Update mainline prebuilts to build 6640873."

Revert submission 1352369-icu-sdk-reland

Reason for revert: conflicts with CLs from vichang@ moving classes around.

Bug: 157734636
Bug: 129332183

Reverted Changes:
I0a0dfa385:Update mainline prebuilts to build 6640873.
I520234e29:Reland "Remove ICU projects for master-art manifes...

Change-Id: I586bc51ebee12023b2b652e5bf2c5988a6a41f33
1302 files changed
tree: 08091d81eb4b3c2b1bfee9042d79af45aadccbd9
  1. appcompat/
  2. common/
  3. mainline/
  4. .gitallowed
  5. adb
  6. Android.mk
  7. update.py