Add support for hot launch in App launch test.

force-stop-app option is added to control hot launch and
cold launch.

Bug: b/73091210

Test:
am instrument -w -r   -e debug false -e launch_directory /sdcard
-e apps "Calculator^Calculator|Clock^Clock" -e trial_launch true
-e log false -e timeout_msec 300000 -e force-stop-app false
-e launch_order CYCLIC -e simpleperf_cmd "simpleperf stat -a"
-e launch_iterations 10 com.android.tests.applaunch/android.test.InstrumentationTestRunner

Change-Id: I4b0f7a61c46e8091e69cad9fa65b5b34f680252d