Check if idsig size is within IncFs limits.

Bug: 152148243
Fixes: 152148243
Test: pm install-incremental <apk in the bug>
Test: atest PackageManagerShellCommandTest PackageManagerShellCommandIncrementalTest IncrementalServiceTest PackageManagerServiceTest ChecksumsTest
Change-Id: I33623a9240482ea36a8e1eeb97ec01294e7249ff
2 files changed