ota-aws: Removing not needed expected print statement

Removing the starting point print statement of the
receiving process as it is not always being printed
and this would lead to test failure, sometimes,
another statement is being printed upon receiving
of a new file block "Index: 9. OTA event id: 6"
in which event id 6 is a mapping to
OtaAgentEventReceivedFileBlock which is triggered
when file block is received.

Signed-off-by: Ahmed.Ismail <Ahmed.Ismail@arm.com>