Update METADATA for 1.5.2 merge am: 68bbe70185 am: f355899f1a am: 286c65b9f2

Original change: https://android-review.googlesource.com/c/platform/external/kotlinx.coroutines/+/1877023

Change-Id: I472caf18983eaf8d1a476354d8beaf08a8c9859d