Revert "Distinguish warm/hot launch by whether the activity has attached process"

This reverts commit 2e039cd3bc020a4d0c5831f945d42e162b9ad5e4.

Reason for revert: Potential culprit for Bug b/171719665

Change-Id: I18e2f1a5eaf1e07b96d6135be56f8077d37b7504
2 files changed