Add cache debugging information to bugreports.

Following the model for dumpsys gfxinfo, this patchset adds a
CacheBinder service that dumps cache state information from each
process.

Bug: 153661880
Test: adb shell dumpsys cacheinfo
Test: adb bugreport

Change-Id: Ie7cce70e56777a200e3e3e92ab895126b6f29032