[ActivityManager] Avoid mistaking visibility by finishing task.

Sympton:
Next activity only adds to history but does not launch/resume then results ANR.

Root Cause:
In a rare timing, some windows are switched at the same time,
it will cause some finishing records on the top temporarily,
then set startIt to false that skip to resume the real top activty.

Solution:
If all activities in a task are finishing, do not use it to check.
The behavior/checking is the same concept as in JellyBean:
            // If starting in an existing task, find where that is...
            boolean startIt = true;
            for (int i = NH-1; i >= 0; i--) {
                ActivityRecord p = mHistory.get(i);
                if (p.finishing) { // <--
                    continue;
                }

Change-Id: I9d81a7b5182400c52e173da23eee61c74692beee
[ActivityManager] Prevent coredump file may not complete for testing.

Sympton:
During testing, skip kill native crash process manually because it will continue to die by default.

Root Cause:
Large process may take some time to do coredump.In auto test, crash process will be killed immediately that results incomplete coredump file.

Solution:
If the tester (IActivityController) will handle app crash event,
Do not kill native crashed process if the rom is debuggable.

Change-Id: Ia360af147d694125d440e5ba2f958c4759a50494