Move ApplicationInfo.usesNonSdkApi to private flags

No need to create an extra field for a boolean flag. Move the recently
added ApplicationInfo.usesNonSdkApi to one bit in privateFlags.

This also solves an issue where the field was not propagated during
copying of the data structure.

Bug: 113315999
Test: phone boots
Change-Id: I09f8f39454c013a84893ac304904a4412fc542bf