cameraservice_test: Add DistortionMapperTest to the host build.

DistortionMapperTest depends on SessionConfigurationUtils, but uses
parts of it that do not rely on a HAL or other device-side information
(components in the android::hardware namespace). This change splits up
SessionConfiguration utils into two files so that functions that do not
rely on a HAL are not bundled with those that do.

Bug: 207411352
Test: Ran test on gLinux.
Change-Id: Iaeeab4ee68044984425a9918a58aa6ce18fc8de4