SideloadOtaStabilityTest throws AssertionError instead of DNAE

SideloadOtaStabilityTest does its own device recovery in order to
prevent devices being stuck in recovery mode after a test failure, but
continuing to throw DNAE after this recovery can lead to devices
becoming permanently marked "unavailable". Using AssertionError instead
allows TF to properly recognize their availability.

Bug: 29011376
Change-Id: Ida777f3a7cc21d2a00a5bd68426e472958705837
1 file changed