While updating errorprone to 2.1.3+, we needed to switch javac classpath to the full classpath in order to avoid resolution errors in errorprone.

This opens the way for accidentally compiling on transitive dependencies rather than explicit dependencies.

Look for a way to switch back the changes to internal_rules.gni here while still maintaining errorprone in working order: https://chromium-review.googlesource.com/c/chromium/src/+/820530