With Android monkey test i cannot test a specific activity, but with Android monkey runner i can do python scripts to simulate a monkey test, so i did a python script open the my activity and init the monkey test :)
#! /usr/bin/env monkeyrunner
from com.android.monkeyrunner import MonkeyRunner, MonkeyDevice
from random import randint
print "get device"
device = MonkeyRunner.waitForConnection()
package = 'my.packaget'
activity = 'my.package.activity'
runComponent = package + '/' + activity
device.startActivity(component=runComponent)
#use commands like device.touch and device.drag to simulate a navigation and open my activity
#with your activity opened start your monkey test
print "start monkey test"
for i in range(1, 1000):
#here i go emulate only simple touchs, but i can emulate swiper keyevents and more... :D
device.touch(randint(0, 1000), randint(0, 800), 'DOWN_AND_UP')
print "end monkey test"
save teste.py and run
$ monkeyrunner teste.py