trusty/apploader: Handle APPLOADER_ERR_NOT_ENCRYPTED

Add a specific error message to the Android CLI tool for the case
where the apploader rejected an attempt to load an application
which requested encryption of its ELF image via its manifest while
containing an unencrypted ELF image.

Bug: 241824652
Change-Id: Ib2a3c881015700492b8166be38c41753bf51b3b2