Add trove4j in prebuilts.

We're going to use the Trove collections in tools/base/perflib. Version 1.1 may
not be recent, but it's the same version that the tools/idea codebase is using.

Change-Id: I48b75c684f28f86a0a0a18dd4df3dfb2f65461e5
Merge "Add trove4j in prebuilts." into idea133
Add artifacts needed for Gradle 2.1

Change-Id: Iec2748e7609e82d3e8360682672403fceadfdfff
Merge "Add artifacts needed for Gradle 2.1" into idea133
add findbugs 3.0.0 and its dependencies.

Change-Id: I0e1da78d9f53d47e9731343eb97d0ba05940ec3f
Merge "add findbugs 3.0.0 and its dependencies." into idea133