Cherry-pick ICU 66.1 from aosp/master

(cherry-picked from commit 923e8487a03c123be9c4deefdebe4906937079cc)

This CL contais squashed changes which update ICU from
version 66.1-rc to 66-1 which update Unicode from
version 13 beta to 13 final.

Changes to ICU include two cherry-picks:

 1. Cherry-pick ICU-20980 BRS66GA Update version numbers and README files
    https://r.android.com/c/1256773
 2. Cherry-pick ICU-20980 integrate CLDR release-36-1 (final) to maint-66
    https://r.android.com/c/1256774

It also includes CL that regenerates ICU data:

 * Regenerate ICU data with ./tools/updateicudata.py
   https://r.android.com/c/1256775/1

Bug: 149845726
Test: cts-tradefed CtsIcuTestCases CtsLibcoreTestCases
      CtsLibcoreOjTestCases CtsLibcoreOjTestCases CtsTextTestCases
      CtsBionicTestCases
Merged-In: I9a44c05b5bbec19c32a5d4483704b35aad048794
Change-Id: Ib745c4f65184c18d1d8ae8e28a1ead55dc959f8a
9 files changed