Update errorprone to 2.11.0

- ./update.sh 2.11.0 9+181-r4173-1 3.15.0
- Changed 2.10.0 -> 2.11.0 in Android.bp
- Removed -Xep:RemovedInJDK11:WARN as it no longer exists
- Add -Xep:EqualNull:WARN because there are a lot of instances of it
- Removed commented out flags

Bug: 190944875
Test: Presubmits
Change-Id: Id3918e24aa45e2b986cbe6f1e866fdd5d3154331
29 files changed