Logs for test & debug blocks

This change adds logging for debuggable and test-only apps when they are
the caller and visibility of another app is blocked due to app
enumeration.

It also adds an adb command to turn logging on and off for other apps to
help developers while debugging issues.

Test: atest AppsFilterTest AppEnumerationTests PackageManagerPerfTest
Bug: 145623959
Change-Id: I1fa930ef40bf08b00c41f51aa25c50b2189395bf