Modify SetDefaultPortParams test

1. For output port in video encoder and input port in video decoder,
it is allowed to configure the size of the buffer. Make adjustments
in the test application to validate this scenario.

2. useBuffer api call is allowed only after sending loaded to idle
state transition command. Ensure this requirement is met.

Test: make vts -j99 BUILD_GOOGLE_VTS=true TARGET_PRODUCT=aosp_arm64 \
&& vts-tradefed run commandAndExit vts \
--skip-all-system-status-check --primary-abi-only \
--skip-preconditions --module VtsHalMediaOmxV1_0Test -l INFO

Bug: 63796949

Change-Id: I1aba7703e1344b87f556d3388a4cde8199898499