Fail package if explicit health check does not pass

As part of extending PackageWatchdog with explicit health check support
in Ib4322c327bcb00ca9a3fbdc83579e7b5f2fd633b. Trigger the observers #execute
method if a package never passed explicit health check on expiry.

Bug: 120598832
Test: atest PackageWatchdogTest
Change-Id: I8e916a6ca115d3883fe29f66456da36cd0ed09fb
2 files changed