toolbox: add prlimit command

adb shell prlimit <pid> <cur> <max>

prlimit uses prlimit internally to allow you to set the limits on an arbitrary
process, if you have the privileges to.

Change-Id: Ie9a5dc510c7c695debd8f948361d4c51befa5604
Signed-off-by: Iliyan Malchev <malchev@google.com>
diff --git a/toolbox/Android.mk b/toolbox/Android.mk
index d8d397e..84714cf 100644
--- a/toolbox/Android.mk
+++ b/toolbox/Android.mk
@@ -176,6 +176,7 @@
     readlink \
     renice \
     restorecon \
+    prlimit \
     rmmod \
     route \
     runcon \