Android: Tell R8 to outline APIs in optional .jar files

Should fix NoClassDefFoundError in androidx.window APIs

Bug: b/326252366
Change-Id: I794a421f906129df7452716b77aabd5f96231312
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5614830


Commit-Queue: Andrew Grieve <agrieve@chromium.org>
Reviewed-by: Sam Maier <smaier@chromium.org>
Auto-Submit: Andrew Grieve <agrieve@chromium.org>
Commit-Queue: Sam Maier <smaier@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1312897}