Android: Replace ConcurrentHashMap usage with Collections.synchronizedMap()

ConcurrentHashMap has a bug on L.
Also adds a checkstyle check to prevent future uses.

Bug: 905903
Change-Id: Ic6afed17b5d7d3c6a150935117fb33e0408955e4
Reviewed-on: https://chromium-review.googlesource.com/c/1407493
Reviewed-by: Tibor Goldschwendt <tiborg@chromium.org>
Commit-Queue: agrieve <agrieve@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#622143}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: b083d66bda71ca14e758550c9edb60ef236770b8
1 file changed