Import Jack coverage release 1.0-b4

Plugin version: 420400 8e3b9010fd5bbf8a2c93dcea40f8eec4c814fcec

Also removes the jack-coverage-plugin-STABLE.jar since we only
support one version of the plugin.

Bugs fixed since 1.0-b3
Bug: 32404357
Bug: 33947199
Bug: 27588651

Test: N/A
Change-Id: I671ae753191b61eb7a350a467de5486d8e2f1955
4 files changed