trusty: apploader: fail specifically if app package is 0 bytes

Replace assert with check and log message.  Also log more about the request if DMA heap allocation fails.

Bug: 315283243
Test: boot to home
Test: touch x && trusty_apploader x
Change-Id: Ic075809fd2a6b09d9c4e8dff986709c4deae8fb7
1 file changed