Don't starting new app instance if failed to kill its old instance

If we've killed an app process but it's not dead, meanwhile we'd need
to start a new instance of this app, we'll hold the creation until
the old instance is gone. If it's been waited for more than 10s,
cancel the creation of the new instance. Also make the waiting here
asynchronized to unblock the process start thread.

Bug: 195955563
Test: Manual - Loop start camera, sleep 1, stop camera app
Test: Manual - Freeze app, then kill & restart & unfreeze
Test: atest CtsAppTestCases
Test: atest FrameworksServicesTests
Test: atest FrameworksMockingServicesTests
Change-Id: I036020366b29cc6da99aebb2e0bc12bf5c337613