DO NOT MERGE: dumpstate: execute procrank using su

procrank is a setuid binary which only exists on userdebug/eng
builds. Instead of executing the setuid binary, run the binary using
the su command. This eliminates one more setuid binary, and allows
the tightening of the SELinux policy.

Bug: 18342188

(cherry picked from commit 2b1f88b6)
Bug: 25951005

Change-Id: I90c86f89974b3878273a29277b2a5d5d7c4b81c7