Isolate CIPD assets for RPI tasks

Isolate CIPD assets for RPI tasks

To verify the assets all end up in the right spot, I wiped all the assets off the phone and then ran
https://chromium-swarm.appspot.com/task?id=36114ccaa41bd810&refresh=10

Overhead comparisons:
Control: 103s https://chromium-swarm.appspot.com/task?id=360e10170744db10

Cold cache: 105s https://chromium-swarm.appspot.com/task?id=36113c4aec720910
Warm cache: 8s https://chromium-swarm.appspot.com/task?id=361143954c1b1c10

Bug:701930
Bug:skia:5213

Change-Id: I1dc052203ed404b63d0a1974ccbe882d26ff9e48
Reviewed-on: https://skia-review.googlesource.com/16490
Commit-Queue: Kevin Lubick <kjlubick@google.com>
Reviewed-by: Eric Boren <borenet@google.com>