Split dumpstate's execution into shorter functions

This is so the code is more modular before we can make a proper binder
service.

Also made the reference to options a constant.

BUG: 111441001
Test: mmm -j frameworks/native/cmds/dumpstate/ && \
  adb push ${OUT}/data/nativetest64/dumpstate_test* \
  /data/nativetest64 && \
  adb shell /data/nativetest64/dumpstate_test/dumpstate_test
Test: adb shell /data/nativetest64/dumpstate_smoke_test/dumpstate_smoke_test
Test: adb bugreport

Change-Id: Ic55c35c11d197e1214d3a3b336803b33579ae5fe