Print package name with "Checking to restart" ProtoLog

Currently, in the "Checking to restart" ProtoLog, only the
activity name is shown, which makes it hard to grep logs on
a per-app level (package name).

This change replaces it with ActivityRecord.toString, which has the
following simple format:

ActivityRecord{<ID> <user> <package name>/<activity name> <task ID>}

Flag: EXEMPT only protolog change
Bug: 400335021
Test: adb logcat
Change-Id: I132903cbd7f6b95a44a4dfa2f36b2f492081dd54