Split up errorprone licenses

Move the Android.bp definition of each dependency jar into its own
directory and give each an accurate license.  Also update
checkerframework/LICENSE from META-INF/LICENSE.txt in
checkerframework/dataflow-errorprone-3.15.0.jar.

Test: m RUN_ERROR_PRONE=1 javac-check
Change-Id: If8d6ea3427266f5f1f2fbb20d7d9bbbedc6cbdc0
6 files changed