Customer API feedback.

Use two separate interfaces for flags and single value. This produces
correct API documentation.

Bug: 160605420
Test: atest PackageManagerShellCommandTest PackageManagerShellCommandIncrementalTest IncrementalServiceTest PackageManagerServiceTest ChecksumsTest
Change-Id: I9a7eaf86af558d8dcfd1636a4baf6a28e2ee79b1
7 files changed