add jacocoagent by default to Java modules

On coverage builds, R8 will fail to properly optimize and fail the build
if ignore_warnings: false, because jacoco injects dependencies on
jacocoagent classes, but the jacocoagent library is not part of the
classpath libraries passed in to R8 in its arguments.

Instead we can add jacocoagent as a libs dependency for these modules so
that it will get pulled into the r8 flags.

Bug: 243903417
Test: m
Change-Id: Icc24cc260b896fc800125a0318308d823ccf7a83