exoplayer bumped minsdk version to 19 am: 7eea9dcc89

Original change: https://googleplex-android-review.googlesource.com/c/platform/external/exoplayer/+/25562793

Change-Id: I43907a9578e8454099ab31f0b7513cfcb02c36ee
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>