Combine jacoco convention plugins into one

[BreakZero]

How I'm testing it

Choose at least one:

• Unit tests
• UI tests
• Screenshot tests
• N/A (provide justification)

Do tests pass?

• [x] Run local tests on DemoDebug variant: ./gradlew testDemoDebug
• [x] Check formatting: ./gradlew --init-script gradle/init.gradle.kts spotlessApply

Is this your first pull request?

• [x] Sign the CLA
• [x] Run ./tools/setup.sh
• [x] Import the code formatting style as explained in the setup script.

[google-cla[bot]]

Thanks for your pull request! It looks like this may be your first contribution to a Google open source project. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

View this failed invocation of the CLA check for more information.

For the most up to date status, view the checks section at the bottom of the pull request.

[dturner]

This will be fixed in #1519