Impose a threshold on the number of attributed op entries returned in a binder call

In the binder call IAppOpsService#getPackagesForOpsForDevice, we return
attributed op entries encapsulated in PackageOps. When there are too
many attribution tags used for a lot of ops, the size of PackageOps can
be bloated and exceeds the binder transaction limit. However, this is
usually caused by DoS attack from malicious apps. A normal app wouldn't
run into this problem.

This CL adds a threshold on the number of attributed op entries that can
be returned in a binder call. The threshold is calculated assuming each
attribution tag is 50 bytes long.

Bug: 372678095
Test: manual. Using provided POC app from the reporter.
Verified the exception is gone after the fix.
Flag: EXEMPT bugfix
Change-Id: I43cd4b9774dbe554edcec296c4b8a3d7fc60c85c