Prebuilts for PMD gradle plugin support.

Include all prebuilt jars required to use the pmd plugin
for gradle. Pulled down the jars by creating a simple pom.xml
with pmd 5.1.1 as a dependency and copying pmd's
dependency files from local repository after running
mvn install.

Tested locally be running the pmd gradle plugin against
some android library projects.

Change-Id: I61fb1ce0c0b9754d21a4e6b3f0ab35c7e80c2d88