Add option to #define _DUMPSTATE_DRY_RUN_ to skip the actual dumps.

(cherry picked from commit 93d705b6d742e8f00167ff2384e35c2205a6f9da)

Such option is useful when debugging dumpstate itself, since it will
finish much sooner and its output will be much smaller.

Change-Id: If821ed21715461bf82eea0b2be4b926239ad69da
3 files changed