libaudiohal: fix get supported parameters queries in HIDL mode

Add a special case for keyStreamSupportedChannels and
keyStreamSupportedSamplingRates in ConversionHelperHidl::keysFromHal().
In this case, the query also contains a key=value pair specifying
the audio format to consider and it must be passed to the audio
HAL including the value.

Bug: 38326193
Test: verify format specifier is sent to HAL for supported sampling
rates and channels queries

Change-Id: I14ac40da920122ec0242ab027a2a4ac1d92381c8