Improve GC pause time reporting

Improve GC pause time reporting, add more timing sections and roots / dirty card scanning pause time for CMS.
Based off of:
https://android-git.corp.google.com/g/#/c/195286/

Change-Id: I42bb8690cba37567b6aabec69e652a5648bd42ae
1 file changed
tree: bb7d86ad3f0f57cc3fd48e92d604ad562396e57e
  1. .gitignore
  2. Android.mk
  3. build/
  4. jdwpspy/
  5. src/
  6. test/
  7. tools/