Add Runner for field-count agent

Add a python script capable of running the field-count agent across
all processes and collecting the results.

Test: m libfieldcounts; ./tools/jvmti-agents/count-fields.py 'Ljava/lang/Class;.extData:Ldalvik/system/ClassExt;'
Change-Id: I7463dfc0b1e7a2ae21836571f3d4708199d1b706
2 files changed