Handle key names in mapping context

BZ: 126002

Mapping context only allows to retrieve a mapping value from its
corresponding key ID. We also want to do the same using its key
as a string.

This patch adds key name handling in context mapping. It also adds
an API to retieve a mapping value from its corresponding key name.

Note: it also removes an unused argument from handleMappingContext
function.

Change-Id: I5a18ad624a69272ea2796090692f2bfa8b373a52
Signed-off-by: Renaud de Chivre <renaud.de.chivre@intel.com>
Reviewed-on: http://android.intel.com:8080/131571
Tested-by: Dixon, CharlesX <charlesx.dixon@intel.com>
Reviewed-by: cactus <cactus@intel.com>
Tested-by: cactus <cactus@intel.com>
4 files changed