update to exoplayer minsdk19 am: 20359810a6

Original change: https://googleplex-android-review.googlesource.com/c/platform/external/exoplayer/+/25388743

Change-Id: I51a516111db12431a0fd0bb292d3a37b00d22049
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>