The system is overwhelmed by an enormous label string returned by
the load label api. This cl truncates the label string if it exceeds
the maximum safe length.
Bug: 67013844
Test: atest PackageManagerTest
Change-Id: Ia4d768cc93a47cfb8b6f7c4b6dc73abd801809bd
Merged-in: Ia4d768cc93a47cfb8b6f7c4b6dc73abd801809bd